C3.1

Question 1

What is the law of conservation of mass?

Answer 1

Atoms cannot be created or destroyed by chemical reactions
The same atoms are present at the start and end of a reaction just joined in different ways
Therefore the total mass stays the same

Question 2

How can you investigate the law of conservation of mass?

Answer 2

Carrying out a reaction in a closed system

Question 3

What is a half equation?

Answer 3

Models the change that occurs for one reactant in a reaction

Question 4

What is an ionic equation?

Answer 4

Shows the ions present in a reaction mixture

Question 5

What is the mole?

Answer 5

The unit for the quantity of a substance

Question 6

What is Avagadro’s constant?

Answer 6

6.02 x 10^23
Number of entities in 1 mole

Question 7

What is an equation for moles with mass?

Answer 7

Moles = mass/mr

Question 8

What is a limiting reactant?

Answer 8

The reactant that is limiting in amount
Determines the amount of product formed

Question 9

What is stoichiometry?

Answer 9

Describes the relative amounts of each substance
Balanced numbers
The big numbers