Chem Chem Chem

Rearrange this equation to isolate c

a = b (1/c - 1/d)

Consider this formula

z = y/z

If z = 4.0 and y = 9.2, what is the value of x?

Use the exponent (EE) functionality on your calculator to do these calculations

(1.6 x 10^4) / (7.2 x 10^-2)

(1.0 x 10^-3) / 7.63

Match the metric prefix with the correct multiplier

cm =

km =

pm =

um =

Mm =

nm =

mm =

Physical Quantity

SI Unit Abbreviation:

mass =

length =

volume =

time =

temperature =

energy =

An aspirin tablet has a mass of 9820.0 mg.

Report the mass of the tablet in (with correct SF):

grams = g

kilograms = kg

micrograms = x 10^6 mu g

centigrams = cg

Indicate whether each of the follow is either a chemical or physical change/property.

1. The melting point of water is 0 degrees C.

2. When an aq solution with a pH less than 7 is added to sodium bicarbonate bubbling occurs.

3. Cooking an egg.

4. The lowering of vapor pressure after salt is added to a liquid.

5. Combination of yellow and blue paint to create a green paint.

6. Formation of solid after reagent combination.

7. Crystal formation upon solution formation.

Fill in the following information for water at 1.00 atm pressure. (4 SF)

1. Freezing Point In degrees C: In K:

2. Boiling Point In degrees C: In K:

An aq sucrose (C12H22O11) solution must be created for an experiment. If 100.00 mL of 0.200 M solution is needed, what amount of sucrose (in grams) must be weighed out? (Hundredths place)

Match the glassware name to its picture

1. Beaker =

2. Erlenmeyer Flask =

3. Volumetric Flask =

4. Graduated Cylinder =

Select all quantities whose values are exact (contains infinite number of significant figures)

1. BP and FP

2. Numbers in a ratio of a metric conversion (ex: 1 L / 1000 mL)

3. Number of trials

4. Masses

5. Density

6. Numbers in a molecular formula

7. Numbers in a mole ratio from a balanced chemical equation

8. Volumes

9. Formula Weight

The following items are required to create a concise informative plot for each of the items listed. (Some terms are used more than once.)

1. Title =

2. Title =

3. Axes =

4. Axes =

5. Data =

6. Data = __________________________________________

A. Best fit line or curve with an equation

B. Reaction, chemicals, or system being investigated

C. Special conditions of the experiment

D. Table with headers containing units

E. Units (if any)

F. Name or symbol of the variable

1. __________ refers to the reproducibility of a measurement and is quantified by calculating the __________ or __________.

2. __________ refers to the closeness of a result to the true value and is quantified by calculating the _. _________________________________

A. percent error B. precision C. error D. mean E. average deviation F. standard deviation G. accuracy __________________________________________

A. precision B. % error C. accuracy D. average deviation E. error F. mean

Use the following information and other sources to match the terms with their definitions.

Scientific inquiry begins when an indiviudal finds a question, generates a hypothesis, and then performs an experiment (an investigation) to test their hypothesis. Data is gathered, organized and processed to find trends and relationships. Inferences, conclusions, and generalizations are made.

Scientific argument occurs after scientific inquiry. The conclusions developed during scientific inquiry become a CLAIM to share with others. The data and results are EVIDENCE that are connected to the claim by REASONING based on scientific laws and theory. The group challenges the relevancy of the evidence, justification, and claim to advance scientific understanding. Claims are modified and more evidence are sought if necessary.

1. Evidence =

2. Claim =

3. Reasoning =

4. Argumentation = __________________________________________

A. a relationship between variables

B. justification that connects data trends to scientific laws or theory

C. construction of scientific ideas by a group of people

D. a conclusion that is supported by the data

Match the statement to one of the three parts of scientific argumentation.

1. Evidence =

2. Reasoning =

3. Claim = __________________________________________

A. Global warming is occurring

B. Satellite & location measurements show a reduction in ice caps

C. Melting is being caused by high atmospheric temperatures

Match the chemical hazard to its description.

1. Corrosive =

2. Flammable =

3. Irritant =

4. Oxidizer =

5. Poison =

6. Sensitizer =

7. Toxic = __________________________________________

A. causes severe immune reaction after repeated exposure

B. easily ignites and burns rapidly

C. irritates living tissue on contact

D. causes adverse health effects

E. may be fatal to humans & animals

F. rapidly oxidizes, can result in combustion

G. destroys living tissue on contact

Match the letter below the GHS symbol to a type of hazard that it represents.

1. Skull =

2. Dead fish =

3. Fireboy =

4. Star on human =

5. Fire =

6. Exclamation mark =

7. Explosion =

8. Ketchup bottle =

9. Handshake = __________________________________________

A. Oxidizer

B. Flammable

C. Explosive

D. Corrosive

E. Fatal

F. Aquatic Toxicity

G. Carcinogen & Toxic

H. Irritant, skin sensitizer

I. Gas under pressure

Based on the GHS information, which chemical is more hazardous?

Chemical: sodium hypochlorite (bleach) Signal Word: danger Hazard & Category: serious eye damage (Category 1) | skin corrosion (Category 1B) __________________________________________

Chemical: ethylene glycol (antifreeze) Signal Word: warning Hazard & Category: acute toxicity, oral (Category 4) | specific organ toxicity (Category 2)

A. ethylene glycol B. not enough information to determine c. sodium hypochlorite

The nine GHS symbols are an improvement over the older NFPA fire diamonds with its 4 sections for hazards. Which GHS symbol would occupy the NFPA sections.

1. Health (blue) =

2. No NFPA Section =

3. Special Hazard (white) =

4. Health (blue) =

5. Flammability (red) =

6. Health (blue) =

7. Instability (yellow) =

8. No NFPA Section =

9. Health (blue) = __________________________________________

A. Skull

B. Dead fish

C. Fireboy

D. Star on human

E. Fire

F. Exclamation mark

G. Explosion

H. Ketchup bottle

I. Handshake

Use the color wheel to determine the solution colors from the colors absorbed.

1. green light absorbed =

2. blue light absorbed =

3. violet light absorbed =

4. red light absorbed =

5. orange light absorbed =

6. yellow light absorbed =

1. An absorption spectrum is a plot of __________ vs _. Lambdamax is the _ .

(first two blanks) A. absorbance B. wavelength C. concentration D. color

(last blank)term-2 A. longest wavelength from the spectrum B. max absorbance value recorded from the spectrum where at the strongest signal C. none of these D. min absorbance value recorded from the longest wavelength E. max wavelength recorded from the spectrum where the signal is strongest __________________________________________

2. A Beer's Law plot is a plot of __________ vs __________ . Beer's Law is _. The slope of Beer's Law is _ and the y-intercept is __________.

(first two blanks) A. absorbance B. wavelength C. concentration D. color

(third blank) A. A =elC B. I = AC + e C. A = eC + l D. C = elA

(last two blanks) A. AC B. 0 C. C D. A E. el F. e G. l __________________________________________

3. If absorbance is measured at a wavelength different than lambdamax, the absorbance at that different wavelength is __________ the absorbance at lambda max.

A. not related to B. less than C. greater than D. equal to __________________________________________

4. If the concentration of the first sample of dye 1 is less than the concentration of a second sample of dye 1, which sample has the highest absorbance? __________

A. the absorbance is the same for both dyes B. not enough information is given C. the second one D. the first one __________________________________________

5. If a solution contains a yellow dye and a blue dye the absorption spectrum will contain __________ .

A. two lambda max one in the red (700 nm) and one in the orange (620 nm) B. a lambda max at the red wavelength (670 nm) C. a lambda max at a green wavelength (520 nm) D. two lambda maxes, one in the blue (470 nm) and one in the yellow (560 nm)

1. A stock solution is a solution _. A standard solution is a solution _.

(first blank) A. all of these B. made by diluting an original solution by a specific volume of solvent C. two of these D. with an accurately known high concentration E. created in a beaker F. made with a solute and an exact volume solvent

(second blank) A. all of these B. created in an Erlenmeyer flask C. which is more dilute than the stock solution D. with higher concentration that the stock solution E. two of these F. created with volumetric glassware

2. When performing a dilution the moles of the stock solution in the volumetric __________ equal the moles of dilution solution in the volumetric __________.

A. graduated cylinder B. flask C. beaker D. pipet

Place the steps for doing the a dilution with volumetric glassware in order.

A. Pre-rinse the volumetric pipet with a small amount of stock solution

B. Remove pipet from stock solution and touch off hanging drops

C. Adjust pressure on the stem until the liquid's meniscus is level to the calibration line

D. Let pipet drain into volumetric flask

E. Fill volumetric flask to calibration line on its neck with solvent

F. Cap flask and invert to mix solution

G. Remove the bulb and place a finger over the stem

H. Pre-rinse the volumetric flask with the solvent

I. Fill the volumetric pipet above the calibration line on its neck

J. Touch off any hanging drops into the flask

Which volume shows the correct number of significant figures when using a 1ml volumetric pipet?

A. 0 mL B. 1.00 mL C. 1 mL D. 1.000 mL

In a previous quarter, students were not given thorough directions for how to make the sucrose standard solutions. so the quality of the plots varied significantly. Choose the comment for each plot that best reflects the quality of that plot at the prompt in Group column. Which calibration plot should be used?

1. Plot: __________

A. 1 B. 2 C. 3 __________________________________________

1. R2 = 0.983 =

2. R2 = 0.993 =

3. R2 = 0.993 =

4. R2 = 0.983 =

A. poor spread data points and good R2 value B. good spread of data points and decent R2 value C. data points only cover a portion of range and good R2 value

A total of 5 standard solution with concentration between 5 to 50 uM are needed to create a Beer's Law Plot for the red dye. The stock solution of the red dye with a concentration of 50 uM will be provided. This solution can be used as the first standard. The other four standards are created by diluting this solution. You can only use a 10 mL volumetric flask and a 1 mL and 5 mL volumetric pipets to create the solutions (once created, the solution can be held in a labelled beaker)

1. What volume of the stock solution (Mconc) is needed to create a 30 uM (Mdil) standard solution? __________

A. 4 B. 1 C. 3 D. 5 E. 2 __________________________________________

2. To make this solution the __________ volumetric pipet(s) are used to deliver the stock solution to the __________.

(first blank) A. 5 mL B. both C. 1 mL

(second blank) A. 10 mL volumetric flask B. 5 mL volumetric pipet C. labelled beaker D. graduated cylinder __________________________________________

3. DI water is then added using a(n) __________ until the __________ of the meniscus is __________.

(first blank) A. beaker B. volumetric pipet C. graduated cylinder D. disposable pipet E. Erlenmeyer flask

(second blank) A. bottom B. top C. middle

(third blank) A. in line with the calibration line on the volumetric flask neck B. in line with the calibration line on the volumetric pipet neck C. above the calibration line on the volumetric flask neck D. above the calibration line on the volumetric pipet neck

1. What percent of known chemicals have safety data sheets (SDS)? __________________________________________

2. Who creates SDS?

A. chemical suppliers B. industrial corporations C. government agencies D. universities __________________________________________

3. What GHS components are incorporated into SDS? A. three of these B. hazard statements C. all of these D. two of these E. signal words F. hazard ratings G. pictograms H. precautionary statements __________________________________________

4. Because SDS __________ legally required to be accurate, one should __________.

(first blank) A. are B. are not

(second blank) A. completely trust the info B. examine the SDSs from diff manufacturers C. read only 1 version D. handle chemicals without SDS carefully __________________________________________

5. SDS are written for __________ setting, because of this chemicals hazards and PPE requirements may be __________. However, the SDS is like Wikipedia, it's a good place to start.

(first blank) A. an industrial B. a medical C. a laboratory course D. a research laboratory

A. just right B. understated C. overstated

Order the steps for using a SDS to fully understand the hazards associated with the chemical.

A. Determine the hazard class: corrosive, flammable, etc. B. Compare label info to ensure you have the right SDS C. Look at the procedures for safe handling

Match the pipet name & function to its picture

1. long, "10" Name: Function:

2. plastic Name: Function: __________________________________________

Name: A. volumetric pipet B. disposable pipet

Function: A. deliver a fixed measured volume B. deliver a variable unmeasured volume

Volumetric pipets & flasks, burets, and graduated cylinders all have markings (lines) etched into the glassware denoting volume levels. Correctly recording the volumes from these pieces of glassware incorporates the following four concepts:

1. Meniscus: The meniscus is the __________ of the liquid surface in the glassware. If the liquid contained in the glassware is polar, adhesion __________ cohesion. leading to a __________ meniscus. If the liquid is nonpolar, adhesion is __________ cohesion, leading to a __________ meniscus.

(first blank) A. tension B. polarity C. level D. curvature

(second + fourth blank) A. less than B. equal to C. greater than

(third blank) A. convex B. concave __________________________________________

2. Parallax error: To avoid parallax error, you must have your eyes level to the __________.

A. center of your goggles B. middle of the glassware C. benchtop D. top or bottom of the meniscus __________________________________________

3. Significant Figures: The number of digits used when recording the volume from each piece of glassware is determined by the _________ for burets and graduated cylinders and by __________ for volumetric pipets and flasks.

A. numbers from markings + a last number estimated between markings B. glassware's total volume C. information provided in the course material D. etched value on glassware (+/1 0.05 mL) __________________________________________

4. Temperature: The temperature of the liquid held by the glassware __________ affect volume measurements, therefore, all liquids should be at __________.

(first blank) A. does not B. does

(second blank) A. 0 Celsius B. 273 K C. the liquid's boiling point D. room temperature

Three groups created Beer's Law plots for the allura red AC dye. The equations for each group's plot are:

Group A: y = 0.2623 x - 0.0016, R2 = 0.9896 Group B: y = 0.2671x + 0.0431. R2 = 0.9780 Group C: y = 0.2598x - 0.0121. R2 = 0.9990

1. Which group(s) probably practiced the most consistent precise technique while malign the standard solutions? __________ Why? __________

(first blank) A. A&C B. B C. none of these D. A&B E. B&C F. A G. C

(second blank) A. The y-intercept is negative B. The y-intercept is the positive C. R2 closest to 1 D. The slope is the smallest E. none of these __________________________________________

2. Which group(s) standard solutions had smudges on the outside of their cuvettes while taking absorbance measures? __________ How can you tell? __________

(first blank) A. A&C B. B C. none of these D. A&B E. B&C F. A G. C

(second blank) A. The y-intercept is negative B. The y-intercept is the positive C. R2 closest to 1 D. The slope is the smallest E. none of these

The Riptide Rush flavor of Gatorade has the following absorption spectrum:

1. What color dyes are present in Gatorade?

A. blue B. red C. two of these D. yellow E. three of these __________________________________________

2. Does each dye have its own lamda max?

A. if they have equal absorbance values they do B. yes C. no __________________________________________

3. If your Beer's Law Plot for the red dye, at what wavelength would you take the absorbance to determine the concentration of red dye is this flavor of Gatorade?

A. 500 nm B. 390 nm C. none of these D. two of these E. all of these F. 630 nm

The image below shows 5 overlaid spectra of the same red dyes. The differences in the spectra are created by the dilution. Which spectra is unreliable? __________ Why? __________

(first blank) A. orange line spectrum B. purple line spectrum C. all are reliable D. green line spectrum E. blue line spectrum F. red line spectrum G. none are reliable

(second blank) A. the absorbance peak is not broad enough B. the jagged line at high absorbance indicates the detector is saturated C. the absorbance peak is too broad D. the low absorbance is difficult to read

A group of students were given the following set of equipment and guiding question. Match the statements to the parts of scientific argument.

1. Evidence =

2. Reasoning =

3. Claim =

A. density determination by 2 different methods

B. the blue & clear objects are the same substance

C. density, an intensive property that characterizes a substance, is similar for the blue & clear object

Should your group change their claim after the poster (argumentation) session?

A. No, collected data is considered factual B. Yes, the claim should always be altered after the poster session C. No, the poster session is a final presentation, not a discussion D. No the claim initiated the investigation so it can't be changed E. Yes, if evidence appears to better support another conclusion F. Yes, if your understanding of how a theory supports a different claim

Choose the appropriate actions to take in the event of a spill

A. Nonvolatile liquid spills require lab evacuation

B. If solid is spilled on skin wash scrape off, then wash with water

C. Use a spill pillow to absorb liquids with nontoxic vapors

D. If splashed with a large quantity of a chemical, use the shower immediately

E. Contaminated clothing must be removed & treated as hazardous waste

F. Spilled solid should be returned to its original bottle

G. Eyewashes should be used for at least 15 minutes

H. If splashed with a large quantity of liquid, wipe of contaminated clothing

I. Use a small brush & dustpan when cleaning up a solid

The following are the key steps for responding to a spill. Match the word with the action.

1. Evacuate =

2. Communicate =

3. Isolate =

4. Mitigate =

A. If possible contain the spill with a spill pillows, sand, etc.

B. If the spill is large and/or hazardous, leave the room or the building

C. Notify an instructor or stockroom staff of the spill location & contents

D. Spill clean up. Your instructor will determine if you are able to assist

Match the titration set up labels to their description

[see image]

Order the steps for buret use.

A. Drain buret into waste container

B. Prerinse with a small amount of titrant

C. Wash buret with dilute soap & then DI water

D. Drain below 0.00 mL to remove air in stopcock

E. Open stopcock to add titrant to analyte

F. Remove hanging drops with tissue

G. Record the final volume to the hundredths place

H. Fill above the 0.00 mL mark

I. Close stopcock, touch buret tip inside of analyte beaker/flask

J. Record the initial volume to the hundredths place

Determine the correct sequence of steps used in carrying out a measurement using a pH probe. Arrange them in order from first to last.

A. Remove probe from storage solution, rinse probe

B. Rinse probe then place in storage solution

C. Place probe in solution being measured

D. Calibrate using 2 or 3 buffers, rinse probe

E. Observe readout of sample solution pH on meter

Match the letters with the parts of a titration curve

[see image]

1. A buffer is a solution containing a weak __________ and its __________ or a weak __________ and its _. A buffer solution _.

(first + second + third + fourth blank) A. Buffer Capacity B. Conjugate Base C. Conjugate Acid D. Acid E. Base

(last blank) A. two of these B. always changes color with pH change C. has a pH of 7 D. resists small changes in pH E. reacts with acid & base solutions __________________________________________

2. The point at which a buffer can no longer resist changes in pH in the presence of acid or base is called the __________.

A. Buffer Capacity B. Conjugate Base C. Conjugate Acid D. Acid E. Base __________________________________________

3. What is a valid way to make an ammonia/ammonium buffer for use in the laboratory? Mix equal volumes of __________

A. 1M NH3 & half as much 1M HCl B. 1M NH3 & 0.01M NH4+ C. two of these D. all of these E. 1M NH3 & 1M HCL F. 1M NH3 & 1M NH4+

The titrations being done in this experiment are acid/base titrations. Either an acid is serving as a titrant and the analyte is a base or the base is serving as a titrant and the analyte is an acid. Because the analyte is a buffer (a mix of a weak acid or base and its conjugate) the reaction with the titrant might be difficult to identify.

1. When the acetic acid / sodium acetate buffer is titrated with NaOH, what is the chemical reaction with the titrant. __________________________________________

2. When ammonia / ammonium chloride buffer is titrated with HCl, what is the chemical with the titrant?

1. When acetic acid / sodium acetate buffer is titrated with NaOH, some of the acetic acid is consumed according to the reaction: CH3COOH + OH- --> CH3COO- + H2O

What chemical reaction occurs after the reaction above to stabilize the pH of the solution in the beaker beneath the buret? __________________________________________

2. When the ammonia / ammonium chloride buffer is titrated with HCl, some of the ammonia is consumed according to the reaction: NH3 + H3O+ --> NH4+ + H2O

What chemical reaction occurs after the reaction above to stabilize the pH of the solution in the beaker beneath the buret?

Calculate the buffer capacity of on the initial gradual change of the pH curve (between 2 or 7 mL added titrant) for a weak acid buffer titrated with 0.1 M NaOH. Buffer capacity has no units. (Report the answer in 2 SF.)

Titrant Vol: 2 mL pH: 3.98

Titrant Vol: 7 mL pH: 6.11

Use the Henderson-Hasselbach equation for the following (3 SF, no units):

1. Calculate the pH of a buffer solution created from 25.0 mL of 0.20 M acetic acid with 0.0350 L of 0.10 M NaOH: ___________

2. How much sodium acetate would you have to add to a solution that contains 10.0 mmol of acetic acid (pKa: 4.72) to make a pH 5.00 buffer? __________

__________ acid is the best choice because it is _. The presence of _ can cause precipitation with some cations or oxidation to __________ in the presence of a strong oxidizing agent, may warrant using __________ acid. ___________ acid should be used as a last resort because it is a strong _. Most acids with a concentration greater than __ and a pH less than _________ are corrosive and can cause damage. When exposed to acid proteins in the skin are damaged and form _which accumulates to _ damage to underlying tissues. Oxidizing agents are also corrosive. Which of the following is not an oxidizing agent? __________

(first blank) A. nitric B. hydrochloric C. sulfuric

(second blank) A. cheapest B. easiest to discard C. most reactive D. least corrosive

(third blank) A. hydronium ions B. nitrate ions C. sulfate ions D. chloride ions

(fourth blank) A. nitrous oxide gas B. nitrogen gas C. oxygen gas D. sulfur dioxide E. sulfur dioxide gas F. chlorine gas G. elemental sulfur solid

(fifth blank) A. nitric B. hydrochloric C. sulfuric

(sixth blank) A. nitric B. hydrochloric C. sulfuric

(seventh blank) A. oxidizing agent B. acid C. decomposer D. buffer

(eighth blank) A. 6 M B. 0.5 M C. 2 M D. 3 M E. 1 M

(ninth blank) A. 1 B. 4 C. 3 D. 5 E. 0 F. 2

(tenth blank) A. soluble skin tissue B. scar tissue C. acid reservoirs D. coagulum

(eleventh blank) A. further B. prevent C. accelerate

(twelfth blank) A. hydrogen peroxide B. potassium permanganate C. most nitrate salts D. ammonium hydroxide E. nitric acid

__________ & __________ hydroxide are _________ which dissolve __________ in water. __________ is _________ dissolved in water. These bases _________ the skin which __________ immediately painful. Skin __________ protective layers when corroded by bases.

(first blank) A. strontium B. iron C. sodium D. calcium

(second blank) A. potassium B. calcium C. ammonium D. lithium

(third blank) A. slightly yellow crystals B. blue powder C. white pellets D. cloudy liquids

(fourth blank) A. easily B. endothermically C. exothermically D. sparingly

(fifth blank) A. potassium B. calcium C. ammonium D. lithium

(sixth blank) A. ammonia solid B. ammonia liquid C. ammonia gas

(seventh blank) A. liquify B. coagulate C. saponify D. scar

(eighth blank) A. may not be B. is

(ninth blank) A. do not form B. slowly form C. form

Which of the following should be done when handling a corrosive?

A. use concentrated solutions whenever possible

B. wear goggles, lab coats & gloves

C. if exposed wash off skin immediately

D. carry bottles in secondary containers

E. wear log sleeved shirts, long paints, & liquid shedding close toed shoes

F. use in the fume hood if the corrosive is an inhalant hazard

G. discard gloves after contamination or taking off

H. know the location of eyewash stations & safety showers

1. What is the vapor pressure of ammonia above a 5.0 M solutions of ammonium hydroxide? __________

A. 0.100 B. 0.86 C. 0.086 D. 1.00 __________________________________________

The IDLH (immediately dangerous to life or health) concentration of ammonia in the air is 300 ppm (parts per million: 300 g per 10^6 g of air)

2. If 0.1 atm is equal to 100,000 ppm, the concentration of ammonia just calculated is __________ ppm. How does the value compare to IDLH? __. Where should you work with ammonium hydroxide in the laboratory? _

(second blank) A. the same B. above C. below

(third blank) A. on the benchtop B. close to the TA C. near the sink D. in the fume hood

Put the steps in order for the dilution of the titrant stock solution. Summarize these steps in your Original Proposal procedures.

A. Fill the volumetric pipet until the meniscus is inline with the etched line on the volumetric pipet

B. Fill the volumetric flask to the calibration line on the neck with DI water

C. Touch of any hanging drops before placing the pipet tip in the 25 mL volumetric flask

D. Determine the volume of stock solution needed for dilution

E. Cap and invert the volumetric flask to mix the new solution

F. Prerinse the volumetric pipet with a small amount of stock solution

G. Obtain a volumetric pipet with a volume equal to the calculated value

H. All the stock solution to flow from the pipet into the volumetric flask

For the Original Proposal you will need two titrant concentrations. You will be given a 0.5 M stock solution which you will use for the first titrant. The second titrant will be created by diluting the 0.5 M stock solution to 0.1 M. What volume of the stock solution will you need to prepare 25 mL of the 0.1 M titrant solution?

What is the [acetate]/[acetic acid] ratio with a pH of 4.39? Provide an answer with 2 SFs.

Error is part of making experimental measurements. Match the following experimental issues to a type of error.

1. random error =

2. instrumental error =

3. personal error =

4. gross error =

5. methodological error = __________________________________________

A. reduced by using a best....

B. inaccurate calibration of...

C. failure to read the last sig...

D. result of equipment fail...

E. consistently reading the...

Error is part of making experimental measurements. Match the following experimental issues to a type of error.

1. random error =

2. instrumental error =

3. methodological error =

4. systematic error =

5. gross error = __________________________________________

A. causes outlier that can be determined by the "Q-Test"

B. eliminated by good experimental methods & more than 1 calibration step

C. light source on the visible spectrometer dims over time

D. measured by calculating estimated standard deviation

E. using a graduated cylinder instead of volumetric glassware to make standard solutions

For each of the following scenarios indicate if the volume needed is an accurate value (the volume needed should have as many SF as possible) or an approximate volume (the volume is just an estimate)

1. 10 mL of buffer needed to calibrate the pH probe =

2. 10 mL volume of solution needed to create a standard solution =

3. 10mL of acetic acid needed to find acetic acid's pH with a pH probe =

4. 1 mL of sodium acetate needed to form a 9:1 acetic acid : acetate buffer =

5. the amount of titrant dispensed from a buret =

6. 1/4 inch of sodium bicarbonate to neutralize lab waste =

Answers: Approximate or Accurate in numbered order

You are evaluating a group's poster during an argumentation session for a new project. Which of the following critiques offered by the travelers to the group spokesperson use scientific concepts, theory, or laws to challenge the group's claim?

Guiding Question: Which chemical equation best represents the reaction of sodium bicarbonate (NaHCO3) with acetic acid (CH3COOH)?

Claim: NaHCO3 + CH3COOH --> H2CO3 + CH3COO- Na+

Evidence:

• Chemical equation balances

• pH paper of resulting solution is neutral

Reasoning: Law of Conservation dictates that the mass of the products has to equal mass of the reactants. H2CO3 is a weak acid and CH3COO- Na+ is a weak base so they cancel each other out, leading to a pH 7 solution.

A. Did you have to add more NaHCO3 to get the pH paper color right?

B. Are you sure mass was conserved? What about the bubbling that occurred when the 2 reagents were combined?

C. How do you know mass is conserved when charges are present in the products?

D. Is the pKa of H2CO3 and the pKb of CH3COO- the same? If they are not, what does that indicate about your claim?

Which of the following play significant roles in the extent of injury or harm when exposed to a hazardous chemical?

A. The relative humidity

B. The amount of time one is exposed to the chemical

C. How the chemical entered the body

D. The amount of chemical one is exposed to

E. The atmospheric pressure

F. The availability of safety equipment

Match the exposure route with a way to minimize exposure occurring through that route.

1. ingestion =

2. eye exposure =

3. inhalation =

4. skin exposure =

5. injection = __________________________________________

A. clean surfaces, wear gloves & lab coat

B. do not put anything in your mouth that has been in lab

C. use a dustpan and a broom to clean up broken glass

D. always wear goggles

E. cap flasks containing volatile liquids

Match the airborne particle with its description.

1. mists =

2. fumes =

3. dusts =

4. smoke =

5. nanoparticles = __________________________________________

A. colloidal suspension of solid or liquid particles in air

B. mixture of dry particles and droplets of liquid

C. tiny droplets of liquid suspended in air

D. solid particles suspended in air

E. ultrafine homogeneous particles ranging in size from 1 to 100 nm

Which of the following are parts of the design of laboratory ventilation?

A. hallway air flows into the lab

B. air enters the labs through heating/cooling ducts and hallway air

C. lab air leaves the lab through fume hoods

D. the atm pressure in the lab is greater than the hallway

E. air exchanges should be at least 24 in 24 hours

1. A NaOH (aq) stock solution was created by dissolving 3.88 g NaOH in water to create a 100.00 mL solution. What is the concentration of this solution? __________ M

2. Perform a tenfold dilution to create three more solutions. What are the concentrations of these solutions?

Dilution #1 =

Dilution #2 =

Dilution #3 =

Why is lambdamax significant?

A. The value indicates the amount of light absorbed

B. The value increases as the energy of light increases

C. The instrument response is highest at that wavelength

D. The value can be used to identify a particular chemical

E. The value can indicate the observed color of solution

Fill in the table with the correct responses.

1. Reaction Order Zero Integrated Rate Law:

Linear Plot:

Rate constant (k) from the linear plot:

Half life (tsub1/2): __________________________________________

2. Reaction Order First

Integrated Rate Law:

Linear Plot:

Rate constant (k) from the linear plot:

Half life (tsub1/2): __________________________________________

3. Reaction Order Second

Integrated Rate Law: Linear Plot:

Rate constant (k) from the linear plot:

Half life (tsub1/2):

The following plot is from a kinetics run of crystal violet and sodium hydroxide.

Which of the following is the pseudo rate law of the reaction?

A. Rate = k [CV+][OH-]

B. Rate = k1

C. Rate = k1[CV+]

D. Rate = k[CV+]^2

E. Rate = k[CV+][OH-]^2

In the FS section of this experiment, you will be instructed to combine the reaction mixture, place it into a cuvette and immediately place it into the spectrometer. The light source in the spectrometer warms the solution inserted into its beam. Warming the solution will change the

A. slope of the linear plot from the integrated rate law

B. reaction order

C. rate constant, k

D. color of the final solution

E. type of reaction occurring

Match Fire Class with the fuel for the fire.

1. A =

2. B =

3. C =

4. D = __________________________________________

A. paper, clothing, plastics

B. gasoline, oil, organic solvents

C. hot plates, computers

D. reactive metals (Na, Li)

Which of the following statements are true about fire?

A. Water can be used to extinguish a class B fire

B. Fire are classified by what type of oxidizing agents are involves

C. Removing heat keeps the fuel from vaporizing

D. The fuel must be vaporized to burn

E. Water cannot be used to extinguish a class D fire

Look up information about bleach, NaOCl (aq). Which of the following are true statements?

A. If a significant amount of bleach is spilled on you, get into the safety shower

B. Beach is a weak reducing agent

C. Bleach forms poisonous chlorine and chloramine gas when combine with ammonia

D. Nitrile gloves have a 480 min breakthrough time for bleach

E. Bleach can cause severe skin burns and eye damage

How does the neutralization process described at the end of Fundamental Skills section in Project #3 differ from the same section in Project #4?

A. The waste from Project #3 has a high pH before neutralization

B. Project #4 calls for HCl solution addition initially

Match each glassware to its proper use. Answer choices are not used more than once.

1. glassware used to accurately transfer small variable volumes =

2. glassware used to accurately transfer small fixed volumes =

3. glassware used to accurately transfer and measure variable volumes =

4. glassware used when contents must be easily accessed =

5. glassware used to prevent splashing or evaporation =

6. glassware used to make and store solutions in known concentration =

Which of the following are possible reasons that you may need to dilute the bleach solution given?

A. the reaction occurs too quickly to get good data

B. The absorbance never decreases

C. The concentration of the dye is too high

D. The temperature of the solution is too low

E. The dye is unreactive

Bleach breaks down dyes, removing color from solution, fabric, etc. Which of the following statements is/are correct?

A. All double bonds are destroyed

B. Triarylmethane dyes react at their center carbon in a way that either separates the 3 aryl groups into 3 different chemicals

C. Blue 1 breaks in two at the zo linkage

D. the extensive pi bonding responsible for HOMO LUMO gaps in the visible region is created

E. Red 40 breaks in two at the azo linkage

Which of the following action should you take if you or a labmate are on fire?

A. use a dinger extinguisher as the first method

B. wrap the person in a fire blanket

C. run out into the hallway to the safety shower

D. stop, drop, & roll

E. others pat the fire with towel or labcoat

The PASS acronym is a useful mnemonic if you have to use a fire extinguisher. Match the first word with the rest of the statement.

1. Pull =

2. Aim =

3. Squeeze =

4. Sweep =

Match the part of the fire tetrahedron with the way to remove it

1. Heat =

2. Oxygen =

3. Chemical chain reaction =

4. Fuel =

Should you use the same balance when making repetitive measurements? Explain.

Which of the following are units of concentration?

• molarity

• mass

• mass %

Which variable is the independent variable? (lab 1) concentration, mass, density

What axis is the independent variable plotted on?

The independent variable is ___ controlled by the experimenter.

What is the goal of the original investigation of Lab 1?

What should the blank be for this experiment? (lab 2)

• water

• solvent

• dye solution

What color of light is being absorbed by a solution?

• usually the color complementary to the observed color

• The observed color of the solution

• Not the observed color of the solution

What is the independent variable in this experiment? (lab 2)

• the absorbance

• the lambda max

• the concentration

What information belongs in the title of the Beer's Law Plot (lab 2)

• the lambda max

• the axes names

• the name of the dye

Besides labeled title and axes, what other piece(s) of information belong on the Beer's Law Plot?

What is the goal of the original investigation? (lab 2)

What is the blank for this experiment? (lab 3)

• water

• crystal violet solution

• sodium hydroxide solution

What color of light is being absorbed by the sample solution? (lab 3)

• purple

• green

• yellow

How is the color absorbed related to the color of the solution? (lab 3)

Why is lambda max programmed into the spectrometer before taking absorbance versus time measurements?

What happened to the leftover solution in the graduated cylinder by the end of the data collection? (lab 3)

What is the goal of the original investigation? (lab 3)

What chemicals are present in the beaker beneath the buret at the equivalence point? (lab 4)

When can you end your titration? (lab 4)

How should the 10 mL of buffer be measured out when checking the pH probe's accuracy? Why? (lab 4)

How should the solutions of acetic acid, sodium acetate, ammonium chloride and ammonium hydroxide be measured out? Why? (lab 4)

Why is it necessary to stir the solution during titration? (lab 4)

What is the goal of the original investigation? (lab 4)