Unit 3.1.2 - Amount of Substance

Question 1

What is the Avogadro’s constant?

Answer 1

The number of particles in one mole of carbon 12

Question 2

What is the molar mass of something?

Answer 2

The mass of one mole of something

Question 3

What formula relates moles and grams?

Answer 3

Moles = Mass (g) /Mr

Question 4

What formula relates moles and volume?

Answer 4

Moles = concentration x volume

Question 5

When using volume in concentration and mole calculation what unit must in be in?

Answer 5

dm3

Question 6

How do you convert cm3 into dm3?

Answer 6

divide by 1000

Question 7

What is the ideal gas equation?

Answer 7

pV = nRT

Question 8

What does each letter stand for in pV = nRT? and what units must each thing be in?

Answer 8

p - pressure in Pa
V - volume in m3
n - number of moles
R - gas constant 
T - temperature in Kelvin

Question 9

What number is the gas constant?

Answer 9

8.31

Question 10

How do you convert KPa into Pa?

Answer 10

x1000

Question 11

How do you convert Celsius into Kelvin?

Answer 11

+273

Question 12

How do you convert cm3 into m3?

Answer 12

x100000

Question 13

How do you convert dm3 into m3?

Answer 13

divide by 10000

Question 14

What does empirical formula show?

Answer 14

The simplest whole number ratio of atoms in a compound

Question 15

What does molecular formula show?

Answer 15

The number of each type of atom in one mole of the compound

Question 16

How do you calculate percentage yield?

Answer 16

(Actual yield / theoretical yield) x100

Question 17

Give two reasons why you never get 100% yield?

Answer 17

1. ) the reaction doesn’t go to completion

2. ) reactants or products are lost

Question 18

How do you calculate percentage atom economy?

Answer 18

(mass of desire products/total mass of products) x100

Question 19

How can you improve percentage atom economy?

Answer 19

Find a use for the other products

Question 20

What are ions with a positive and negative charge called?

Answer 20

Positive - cation

Negative - anions

Question 21

Name five common anions?

Answer 21

hydroxide, sulphate, carbonate, nitrate and hydrogencarbonate