Calculations Using On Balenced Equations (write On Paper If Needed)

Question 1

Silicon carbide, SiC, which is used as an abrasive on sandpaper, is prepared using the chemical reaction.

3C+SiO2 ~~> 2CO+SiC

How many grams of SiC can be produced from 15.0 g of C?
(Write on paper if needed)

Answer 1

Ratio: 3:1
3= 3C
1= Sic

3C+SiO2 ~~> 2CO+SiC

M=15g M=1.25 ÷ 3= 0.42g (divide by ratio)

N=15÷12=1.25 N= 15.12g

GFM= GFM=
C 1x12 Si 1x24
12 24
=12 C 1x12
12
=36x0.42= 15.12g

Question 2

The chemical equation for the photosynthesis reaction in plants is:

6H2O+6CO2 ~~> C6H12O6+6O2

How many grams of H,O reacts with 20.0 g of CO,?
(Write on paper if needed)

Answer 2

Ratio: 6:6 1:1
1= 6H2O
1= 6CO2

6H2O+6CO2 ~~> C6H12O6+6O2

M= 18x0.45 M= 20g
=8.1g
N= 0.45 N= 20/44= 0.45

GFM= GFM=
H 2x1 C 1x12
2 12
O 1x16 O 2x16
16 32
=18x0.45=8.1 =44

Question 3

Decomposition of KCIO, serves as a convenient laboratory source of small amounts of oxygen gas. The reaction is:

2kClO ~~> 2kCl+3O2

What mass of KCIO, must be heated to produce 8 g of O,?
(Write on paper if needed)

Answer 3

Ratio: 2:3
2= 2KClO3
3= 3O2

2kClO ~~> 2kCl+3O2

M= 19.6g M= 8g

N= 0.25= 3= N= 8÷32=0.25
0.08x2= 0.16

GFM= GFM=
K 1x39 O 2x16
39 32
Cl 1x35.5 =8÷32= 0.25
35.5
O 3x16
48
=122.5x0.16