Unit 4 Stoichiometry

Question 1

The steps to calculate reacting masses

Answer 1

1) identify 2 substances
2)
- n =
- m =
- Mr =

Question 2

Definition- limiting reactant

Answer 2

• the reactant that is used up first

Question 3

Definition- Excess Reactants

Answer 3

a reactant that comes in excess so that ALL of the other reactant can fully react

Question 4

Mg + 2HCl —- MgCl₂ +H₂
- 4.8g of Mg ribbon reacts with a solution of HCl acid containing 7.3 of HCl
- Which reactant is the limiting reactant?

Answer 4

Mg
n- 0.2
m- 4.8
Mr- 24

HCl
n- 0.2
m- 7.8
Mr- 36.5

Ration of Mg : HCl
1 : 2
0.2 : 0.4