1.2 Amount of substance (need to add unit conversions)

Question 1

Define relative molecular mass

Answer 1

Average mass of naturally occurring isotopes of a compound compared to 1/12 the mass of an atom of carbon 12

Question 2

Define relative atomic mass

Answer 2

Average mass of all isotopes of an atom compared to 1/12 the mass of an atom of carbon 12

Question 3

Define Avogadro’s constant

Answer 3

Number of particles/atoms/ions in one mole of a substance

Question 4

Equation with mass of 1 mol, mass of 1 atom and avogadros

Answer 4

Mass of 1 mol = mass of 1 atom/molecule X avogadro

Question 5

Define percentage yield

Answer 5

The % of product produced by a reaction, compared to a theoretical maximum

Question 6

How would you calculate percentage yield

Answer 6

Actual yield / theoretical yield X 100

Question 7

What can the percentage yield of a practical be used to investigate

Answer 7

Efficiency of practical techniques and whether reactions proceed as estimated

Question 8

Define atom economy

Answer 8

% of amount of reactants made into a certain (useful) product

Question 9

How would you calculate atom economy

Answer 9

Mr of desired product / Mr of total reactants

Question 10

What can the atom economy of a reaction be used to investigate

Answer 10

Efficiency of using a specific reaction to produce a product

Question 11

Ideal gas equation with units

Answer 11

PV = nRT
Pressure x Volume = Number of moles x Gas constant x Temperature

P - Pa
V - m^3
T - K
R - 8.31

Question 12

What are standard conditions

Answer 12

25C / 298K
1 atm/100kPa

Question 13

How do you convert between K and C temperatures

Answer 13

C –> K +273
K –> C -273

Question 14

Define empirical formula

Answer 14

Simplest whole number ratio of atoms in a compound

Question 15

Equation linking moles concentration and volume

Answer 15

Moles = conc x volume

Question 16

Equation linking moles, mass and mr

Answer 16

Moles = mass/mr