C2 Amount Of Substances

Question 1

Define Atomic mass

Answer 1

The mass of an atom, typically expressed in atomic mass units (amu).

Question 2

Define relative molecular mass

Answer 2

The mass of a molecule compared to one-twelfth of the mass of a carbon-12 atom.

Question 3

Define Avogadro’s constant

Answer 3

The number of particles in one mole of a substance, approximately 6.022 x 10²³.

Question 4

What is the formula for moles?

Answer 4

moles = mass/Mr

Question 5

What is the formula for concentration?

Answer 5

concentration = moles/volume

Question 6

What is the ideal gas equation?

Answer 6

pV = nRT

Question 7

What does ‘p’ represent in the ideal gas equation?

Answer 7

Pressure (Pa)

Question 8

What does ‘V’ represent in the ideal gas equation?

Answer 8

Volume (m³)

Question 9

What does ‘n’ represent in the ideal gas equation?

Answer 9

The amount of moles

Question 10

What does ‘R’ represent in the ideal gas equation?

Answer 10

The gas constant, 8.31

Question 11

What does ‘t’ represent in the ideal gas equation?

Answer 11

Temperature (Kelvin)

Question 12

Define empirical formula

Answer 12

The simplest whole number ratio of atoms of each element in a compound.

Question 13

Define molecular formula

Answer 13

The actual number of atoms of each element in a compound.

Question 14

What is the percentage atom economy formula?

Answer 14

(Mr of desired product)/(Mr of all reactants) x 100

Question 15

What is the percentage yield formula?

Answer 15

Percentage yield = (actual yield/theoretical yield) x 100