2.1.3 Amount Of Substance

Question 1

Amount of substance definition

Answer 1

Quantity used to count number of particles in a substance, measured in mol.

Question 2

What is a mole?

Answer 2

One mole is the amount of a substance that contains 6.02 X 10^23 particles

Question 3

What is Avogadro’s constant

Answer 3

The number of particles in 12g of carbon-12, 6.02 X 10^23.

Question 4

What is molar mass

Answer 4

Mass per mole of substance, measured in g mol^-1.

Question 5

Equation linking mass, amount and molar mass.

Answer 5

Mass = Mr X mol

Question 6

Empirical formula definition

Answer 6

Simplest whole number ratio of atoms of each element in a compound

Question 7

Molecular formula definition

Answer 7

Number of atoms of each element in a molecule

Question 8

Water of crystallisation definition

Answer 8

When water molecules are part of a crystalline structure.

Question 9

Hydrated definition

Answer 9

Any compound containing water

Question 10

Anhydrous definition

Answer 10

Compound without water

Question 11

Molar gas volume units

Answer 11

Dm^3 mol^-1

Question 12

Equation linking concentration, amount and volume.

Answer 12

Mol = conc X vol

Question 13

What’s a standard solution

Answer 13

Solution of known concentration

Question 14

What is molar gas volume

Answer 14

Volume per mole of gas molecules at a stated temp and pressure

Question 15

What is RTP

Answer 15

About 20 C and 101KPa (1atm)

Question 16

Equation linking amount and gas vol

Answer 16

Vol = mol X 24 dm^3

Question 17

What’s the ideal gas equation?

Answer 17

pV = nRT

Question 18

What are the assumptions made for molecules making up an ideal gas?

Answer 18

Random motion
Elastic collisions
Negligible size
No IMF

Question 19

What is V measured in in the ideal gas equation?

Answer 19

M^3

Question 20

What is P measured in in the ideal gas equation

Answer 20

Pa

Question 21

What is T measured in in the ideal gas equation

Answer 21

Kelvin

Question 22

Celsius to kelvin

Answer 22

C + 273

Question 23

Cm^3 to M^3

Answer 23

X 10^-6

Question 24

Cm^3 to M^3

Answer 24

X 10^-6

Question 25

Dm^3 to M^3

Answer 25

X 10^-3

Question 26

What is stoichiometry of the reaction

Answer 26

The ratio of the amount of each substance

Question 27

Percentage yield equation

Answer 27

Actual yield/theoretical yield X 100%

Question 28

Limiting reagent definition

Answer 28

Reactant not in excess and will be completely used up first and stop the reaction

Question 29

Atom economy equation

Answer 29

Sum of molar masses of desired products/ sum of molar masses of all products X 100%

Question 30

How would a high atom economy be sustainable

Answer 30

Makes industrial processes more efficient, preserves raw materials and reduces waste.