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Chemistry

Acids base and salts

Formulas [Chemical Equation]

aqueous > 2 elements mixed together to form a thing.

all acids (aq)

Acid (aq) + base(alkali) → water (l)+ salt (aq/s)

Acid (aq) + carbonate → salt +water (l) +CO2

Acid + Metal → salt + hydrogen

base(aq)+ ammonium salts(aq) → salt + water + ammonia(g)

hydroxide →OH^-

sulfate→SOv4^[2-]

nitrate →NOv3[-]

carbonate →COv3[2-]

ammonium →NHv4[+]

ammonia (g)→ NH3 !NO CHARGE!

hydrochloric acid (aq)→ HCl !NO CHARGE!

sulfuric acid (aq) → H2SOv4 !NO CHARGE!

nitric acid (aq) → HNOv3 !NO CHARGE!

ethanoic acid (aq) → CHv3COOH !NO CHARGE!

carbon dioxide → CO2 !NO CHARGE!

water → H2O

Ammonium (NH4) salts contains nitrogen.

Strong acids are lab (sulfuric, nitric & hydrochloric acid) > ionise completely in water to produce hydrogen [H+] ions

Weak acids are citric, ethanoic acid > ionise partially in water to produce hydrogen[H+] ions)

Properties of acids

-Acids have a sour taste

-Acids can conduct electricity

-Acids turns blue litmus paper red

-Acids are corrosive if concentrated

*all acids contain hydrogen. Not all compounds contain hydrogen = acids

e.g. ammonia;NHv3 , Methane; CHv4 [Do not produce hydrogen ions in WATER (aq)]

Bases > metal oxide + hydroxide / alkaline + soluble. *sodium hydroxide

Properties of alkalis/bases

- Alkalis have a bitter taste and feels soapy

- Alkalis turn red litmus paper blue

-Alkalis conduct electricity

-Alkalis are corrosive when concentrated.

-Alkalis reacts with acids to form salt and water ONLY.

alkali + acid→ salt + water

Test for different …


pH Scale

colour

acidic/alkaline

higher concentration of?

Red 0-2

Most acidic

Hydrogen ions

Orange 3-4

Acidic

Hydrogen ions

Yellow 5-6

Least acidic

Hydrogen ions

Green 7

Neutral

-

Blue 8-11

Least alkaline

Hydroxide ions

Violet 12-14

Most alkaline

Hydroxide ions

We can measure pH by using:

  1. chemical compound; indicator

  2. pH sensor attached to data logger

  3. pH meter

pH of soil should be between 5-9 to grow well > Most grow well in neutral soil/slightly acidic

pH of soil unsuitable for plant growth due to : too much fertiliser added to the soil or environmental pollution such as acidic rain.

We can control acidity by ‘liming’ the soil. [Bases such as quicklime (calcium oxide) or slacked lime (calcium hydroxide) *Do not add too much. Too alkaline = unsuitable

Universal Indicator

Litmus paper turns red/remains red > acidic/neutral

Litmus paper turns blue/remains blue > alkaline/neutral

pH range -indicator changes colour : 5-8

Test for Hydrogen -add magnesium ribbon-

-Place a lighted splint at the mouth of test tube

-Hydrogen gas extinguish lighted splint with a ‘pop’ sound.

copper + silver → no reaction (unreactive) layer is insoluble in water, is formed and coated around the metal.

Test for Carbon Dioxide -add calcium carbonate to liquid-

-bubble gas through limewater

-COv2 forms white precipitate with limewater.

precipitate = insoluble particles produced in liquid by chemical reaction.

Test for Oxygen

Place a glowing splint at the mouth of the reaction, glowing splint should relight.

Sure! Here's a mnemonic to help you remember the process of calculating molar mass in chemistry:

M - Multiply: Multiply the atomic mass of each element by the number of atoms present. O - Obtain: Obtain the atomic masses from the periodic table. L - List: List all the elements and their respective atomic masses. C - Calculate: Calculate the molar mass by adding up the individual atomic masses.

To remember this, you can use the mnemonic: "Multiply, Obtain, List, Calculate" or simply "MOLC."

By using this mnemonic, you can easily recall the steps involved in calculating molar mass in chemistry.

Mol Calculation in Chemistry

  • Mol (short for mole) is a unit used in chemistry to measure the amount of a substance. It represents a specific number of particles, which is approximately 6.022 x 10^23, known as Avogadro's number.

  • Molar Mass: The molar mass of a substance is the mass of one mole of that substance. It is calculated by summing the atomic masses of all the atoms in the chemical formula. The unit of molar mass is grams per mole (g/mol).

  • Mole-Particle Conversion: To convert between moles and particles (atoms, molecules, ions), we use Avogadro's number. The number of particles is equal to the number of moles multiplied by Avogadro's number.

  • Mole-Mass Conversion: To convert between moles and mass, we use the molar mass. The mass is equal to the number of moles multiplied by the molar mass.

  • Mole-Volume Conversion: To convert between moles and volume, we use the ideal gas law. The volume is equal to the number of moles multiplied by the molar volume of the gas at a given temperature and pressure.

  • Stoichiometry: Stoichiometry is the calculation of the quantities of reactants and products in a chemical reaction. It is based on the balanced chemical equation and involves mole-to-mole ratios.

  • Percent Composition: Percent composition is the percentage by mass of each element in a compound. It is calculated by dividing the mass of each element by the total mass of the compound and multiplying by 100.

  • Empirical Formula: The empirical formula represents the simplest whole number ratio of atoms in a compound. It can be determined from the percent composition or experimental data.

  • Molecular Formula: The molecular formula represents the actual number of atoms of each element in a compound. It is a multiple of the empirical formula and can be determined using the molar mass.

  • Limiting Reactant: The limiting reactant is the reactant that is completely consumed in a chemical reaction, limiting the amount of product that can be formed. It can be determined by comparing the mole ratios of the reactants.

  • Yield: The yield is the amount of product obtained in a chemical reaction. It can be expressed as a percentage of the theoretical yield, which is the maximum amount of product that can be formed based

Acids base and salts

Formulas [Chemical Equation]

aqueous > 2 elements mixed together to form a thing.

all acids (aq)

Acid (aq) + base(alkali) → water (l)+ salt (aq/s)

Acid (aq) + carbonate → salt +water (l) +CO2

Acid + Metal → salt + hydrogen

base(aq)+ ammonium salts(aq) → salt + water + ammonia(g)

hydroxide →OH^-

sulfate→SOv4^[2-]

nitrate →NOv3[-]

carbonate →COv3[2-]

ammonium →NHv4[+]

ammonia (g)→ NH3 !NO CHARGE!

hydrochloric acid (aq)→ HCl !NO CHARGE!

sulfuric acid (aq) → H2SOv4 !NO CHARGE!

nitric acid (aq) → HNOv3 !NO CHARGE!

ethanoic acid (aq) → CHv3COOH !NO CHARGE!

carbon dioxide → CO2 !NO CHARGE!

water → H2O

Ammonium (NH4) salts contains nitrogen.

Strong acids are lab (sulfuric, nitric & hydrochloric acid) > ionise completely in water to produce hydrogen [H+] ions

Weak acids are citric, ethanoic acid > ionise partially in water to produce hydrogen[H+] ions)

Properties of acids

-Acids have a sour taste

-Acids can conduct electricity

-Acids turns blue litmus paper red

-Acids are corrosive if concentrated

*all acids contain hydrogen. Not all compounds contain hydrogen = acids

e.g. ammonia;NHv3 , Methane; CHv4 [Do not produce hydrogen ions in WATER (aq)]

Bases > metal oxide + hydroxide / alkaline + soluble. *sodium hydroxide

Properties of alkalis/bases

- Alkalis have a bitter taste and feels soapy

- Alkalis turn red litmus paper blue

-Alkalis conduct electricity

-Alkalis are corrosive when concentrated.

-Alkalis reacts with acids to form salt and water ONLY.

alkali + acid→ salt + water

Test for different …


pH Scale

colour

acidic/alkaline

higher concentration of?

Red 0-2

Most acidic

Hydrogen ions

Orange 3-4

Acidic

Hydrogen ions

Yellow 5-6

Least acidic

Hydrogen ions

Green 7

Neutral

-

Blue 8-11

Least alkaline

Hydroxide ions

Violet 12-14

Most alkaline

Hydroxide ions

We can measure pH by using:

  1. chemical compound; indicator

  2. pH sensor attached to data logger

  3. pH meter

pH of soil should be between 5-9 to grow well > Most grow well in neutral soil/slightly acidic

pH of soil unsuitable for plant growth due to : too much fertiliser added to the soil or environmental pollution such as acidic rain.

We can control acidity by ‘liming’ the soil. [Bases such as quicklime (calcium oxide) or slacked lime (calcium hydroxide) *Do not add too much. Too alkaline = unsuitable

Universal Indicator

Litmus paper turns red/remains red > acidic/neutral

Litmus paper turns blue/remains blue > alkaline/neutral

pH range -indicator changes colour : 5-8

Test for Hydrogen -add magnesium ribbon-

-Place a lighted splint at the mouth of test tube

-Hydrogen gas extinguish lighted splint with a ‘pop’ sound.

copper + silver → no reaction (unreactive) layer is insoluble in water, is formed and coated around the metal.

Test for Carbon Dioxide -add calcium carbonate to liquid-

-bubble gas through limewater

-COv2 forms white precipitate with limewater.

precipitate = insoluble particles produced in liquid by chemical reaction.

Test for Oxygen

Place a glowing splint at the mouth of the reaction, glowing splint should relight.

Sure! Here's a mnemonic to help you remember the process of calculating molar mass in chemistry:

M - Multiply: Multiply the atomic mass of each element by the number of atoms present. O - Obtain: Obtain the atomic masses from the periodic table. L - List: List all the elements and their respective atomic masses. C - Calculate: Calculate the molar mass by adding up the individual atomic masses.

To remember this, you can use the mnemonic: "Multiply, Obtain, List, Calculate" or simply "MOLC."

By using this mnemonic, you can easily recall the steps involved in calculating molar mass in chemistry.

Mol Calculation in Chemistry

  • Mol (short for mole) is a unit used in chemistry to measure the amount of a substance. It represents a specific number of particles, which is approximately 6.022 x 10^23, known as Avogadro's number.

  • Molar Mass: The molar mass of a substance is the mass of one mole of that substance. It is calculated by summing the atomic masses of all the atoms in the chemical formula. The unit of molar mass is grams per mole (g/mol).

  • Mole-Particle Conversion: To convert between moles and particles (atoms, molecules, ions), we use Avogadro's number. The number of particles is equal to the number of moles multiplied by Avogadro's number.

  • Mole-Mass Conversion: To convert between moles and mass, we use the molar mass. The mass is equal to the number of moles multiplied by the molar mass.

  • Mole-Volume Conversion: To convert between moles and volume, we use the ideal gas law. The volume is equal to the number of moles multiplied by the molar volume of the gas at a given temperature and pressure.

  • Stoichiometry: Stoichiometry is the calculation of the quantities of reactants and products in a chemical reaction. It is based on the balanced chemical equation and involves mole-to-mole ratios.

  • Percent Composition: Percent composition is the percentage by mass of each element in a compound. It is calculated by dividing the mass of each element by the total mass of the compound and multiplying by 100.

  • Empirical Formula: The empirical formula represents the simplest whole number ratio of atoms in a compound. It can be determined from the percent composition or experimental data.

  • Molecular Formula: The molecular formula represents the actual number of atoms of each element in a compound. It is a multiple of the empirical formula and can be determined using the molar mass.

  • Limiting Reactant: The limiting reactant is the reactant that is completely consumed in a chemical reaction, limiting the amount of product that can be formed. It can be determined by comparing the mole ratios of the reactants.

  • Yield: The yield is the amount of product obtained in a chemical reaction. It can be expressed as a percentage of the theoretical yield, which is the maximum amount of product that can be formed based