Principles of Chemistry I - Final Exam Study Guide

Which is a heterogeneous mixture?

Which is a homogeneous mixture?

Which is a pure substance?

T or F: Every substance has at least 1 differentiating characteristic.

Which 2 of these are requirements for differentiating characteristics?

A) Are intensive B) Are extensive C) Are unique for each substance D) Change depending on environment (temp, pressure, etc)

List some good differentiating characteristics

List some bad differentiating characteristics

Is it intensive or extensive? -- Chemical reactions

A) Intensive B) Extensive

Is it intensive or extensive? -- Temperature

A) Intensive B) Extensive

Is it intensive or extensive? -- Density

A) Intensive B) Extensive

Is it intensive or extensive? -- Volume

A) Intensive B) Extensive

If you put a balloon in liquid nitrogen, what happens to the balloon?

During a phase change, energy is ____________ stored/released by the system.

A) Sometimes B) Never C) Always

The amount of energy exchanged per unit mass of a substance is a ______________.

A) Phase change B) Triple point C) Vaporization D) Differentiating Characteristic

Where are the phase changes occurring?

A) Between A&B, and D&E B) Between A&B, and C&D C) Between C&D, and E&F D) Between B&C, and D&E

Where is PE increasing a lot? A) Between A&B, and D&E B) Between A&B, and C&D C) Between C&D, and E&F D) Between B&C, and D&E

Where is KE increasing a lot? A) Between A&B, and D&E B) Between A&B, and C&D C) Between C&D, and E&F D) Between B&C, and D&E

Phase stability relies on...

A) The number of molecules B) Potential energy C) Pressure & Temperature D) Pressure only

What is an example of a liquid that evaporates (to a certain extent) at any temp?

Boiling point occurs when ________ equals ________.

On a vapor pressure graph, the left side of one of these lines represents what phase?

Which of these is most volatile?

A separating method based on the mechanical separation of substances in the solid-state from substances in a fluid phase (liquid or gas) by using a physical barrier which only the fluid can pass.

This technique is used to separate substances in a liquid mixture taking advantage of differences in the boiling points of the various components. It involves a phase change from liquid to gas and the reconversion of the separated substances to the liquid phase.

A separation method that includes changing the temperature or the concentration of the components in a fluid (liquid or gas) mixture, or by adding other substances to include a solid-state.

In the ideal gas law, changing mass changes speed, but does not change___________.

In the ideal gas law, changing temperature changes pressure and ________.

T or F: The movement of gas particles in the ideal gas law is uniform and predictable.

Pressure = Force/?

A measure of the average KE per particle.

What is the average KE for a 1kg particle moving at 4 m/s?

KE = (1/2) * m * v^2

At the same temperature, the speed of different particles will depend on the __________.

In a "% of particles v velocity" graph, the substance with the HIGHEST mass can be found by....

In a "% of particles v velocity" graph for molecules with different masses, the substance with the LOWEST mass can be found by....

In a "% of particles v velocity" graph for molecules with different temperatures, the substance with the higher distribution of velocities (aka a "less steep" curve) might have a...

In a "% of particles v velocity" graph for molecules with different temperatures, the substance with the HIGHEST temperature can be found by....

T or F: In a "% of particles v velocity" graph, you shouldn't look at the one with the highest mountain, you should look at the one that has the peak at the highest velocity (when looking for highest temperature or smallest mass)

T or F: Substances at the same temperature will have the same KE, regardless of mass.

What graph is this?

What graph is this?

T or F: The average KE of a substance changes during a phase change.

T or F: Ionic compounds are not molecules.

For gases of equal temperature (𝑇),(T), pressure (𝑃),(P), and volume (𝑉),(V), the number of _________ of the gases is equal as well.

Gases that represent the ideal gas law are at a high ________ and low __________.

A) Temperature, Mass B) Pressure, Temperature C) Number of moles, Volume D) Temperature, Pressure

Use Kb when your amount of substance is given in...

A) Molecules B) Moles C) Neither

Use R when your amount of substance is given in...

A) Molecules B) Moles C) Neither

If you raise temperature and the strength of IMFs, what happens to the pressure?

A) No change B) Increase C) Decrease

The strength of intermolecular forces depends on the ____________ between particles.

At a single temperature, the substance with the _________ vapor pressure has the highest IMFs.

A) Highest B) Lowest C) Neither

Phase changes depend on how _________ and ________ are distributed

A) pressure, temperature B) mass, IMFs C) volume, temperature D) energy, matter

PE depends on the _________ and ___________ of interactions between particles.

For ATTRACTION, closer molecules means....

For REPULSION, closer molecules means....

During a phase change, all energy is invested or lost in the form of ___________.

A) Heat B) KE C) PE D) None of the above

T or F: The size of the particles matters when considering the PE needed to separate two atoms.

When turning a liquid into a gas, we must _________ PE in order to separate the two atoms.

A) Add B) Subtract C) Do nothing to

When a system can adopt different states, the one it picks depends on...

A system wants to be in a place with the _________ PE and _________ # of configurations

A) Highest, highest B) Lowest, highest C) Highest, Lowest D) Lowest, Lowest

In PEC diagrams, a substance is looking for __________ and _________ stability

Lower pressures favor states with a ___________ # of configurations.

What is the key differentiating characteristic between substances?

T or F: If T, V, and P is the same for 3 gases, the number of mols must be the same for all of them.

Higher temps prefer a ________ PE.

A) Higher B) Lower

1 m^3

T or F: Most space in the atom is taken up by the nucleus.

T or F: Most space in the atom is taken up by the electron cloud.

T or F: Most of the mass of the atom comes from the nucleus.

T or F: Most of the mass of the atom comes from the electron cloud.

This number refers to the number of protons in the nucleus, but also refers to the number of electrons of the atom if it's in a neutral state.

In a neutral atom, __________ = ___________.

A) Protons, neutrons B) Protons, electrons C) Neutrons, electrons D) None of the above

The mass of an atom can be determined by adding the number of __________ and ___________.

A) Protons, neutrons B) Protons, electrons C) Neutrons, electrons D) None of the above

T or F: Protons and neutrons have about the same mass.

T or F: Atoms that are isotopes have the same number of protons, but a different number of neutrons.

How do you write the atomic symbol of an element?

Average atomic mass (mass of an element on the PT) is equal to the...

A) Protons + neutrons of every isotope B) Number of electrons C) Percent abundance only D) Mass times relative abundance

In a mass spectrometry graph, all fragments are __________ charged.

A) Positively B) Negatively C) Neutral

Type and number of atoms of each type per particle.

Steps for Finding the Empirical Formula

How do you convert the empirical formula to the molecular formula?

A substance is 50 amu. If the empirical formula of this substance is X2Y3, and the mass of X2Y3 is 25 amu, what is the molecular formula of this substance?

If you're trying to find the molecular formula of a mass spec, the mass of the substance is the peak on the farthest...

A) Left B) Center C) Right D) None of the above

Energy travelling through space as waves formed by oscillating electric and magnetic fields

The period of a wave, inverse to frequency, and denoted by ƛ

A) Wavelength B) Frequency C) Wavenumber

The number of waves per unit time, inverse to wavelength, and denoted by v

A) Wavelength B) Frequency C) Wavenumber

Speed of light = ________ x _____________

In absorption spectroscopy, the color that is released is the wavelength with the ___________ absorption.

A) Highest B) Medium C) Lowest

Absorption is highest when transmittance is ___________.

A) Highest B) Medium C) Lowest

In an emission spectrum, more lines of emission corresponds to a _____________ molar mass.

A) Higher B) Medium C) Lower

Any state above ground state for an atom.

The lowest energy state of an atom

Absorption occurs when the energy is __________.

A) Increasing B) Decreasing C) Remaining the same

Emmission occurs when the energy is __________.

A) Increasing B) Decreasing C) Remaining the same

Frequency is __________ as bond strength is increasing.

A) Increasing B) Decreasing C) Remaining the same

Frequency is __________ as mass is increasing.

A) Increasing B) Decreasing C) Remaining the same

Total energy is __________ during a bond formation.

A) Increasing B) Decreasing C) Remaining the same

Energy = ________ * __________ (use v)

Energy = ________ * __________ (use ƛ)

The equation E = hc/ƛ gives you an answer with what unit?

If you have energy in units of J/photon, how do you find the energy of 1 mol?

Microwaves are usually associated with a change in _________________.

A) excitation/bond breaking state B) vibrational state C) rotational state