wayground logo

Free Printable Worksheets

Font size

S
M
L
XL
Worksheets

Practice Quiz: Balancing Equations & Calculations

Total questions: 10

Worksheet time: 20mins

Name
Class
Date
1.

Sodium (Na) burns in oxygen (O2) to form sodium oxide (Na2O).

What is the balanced symbol equation for this reaction?

a)

4Na + 2O -> 2Na2O

b)

4Na + O2-> 2Na2O

c)

2Na2 + O2 -> 2Na2O

d)

2Na2 + 2O -> 2Na2O

2.

Solid sodium metal (Na) reacts with water (H2O) to form an aqueous solution of sodium hydroxide (NaOH) and hydrogen gas (H2).

Which symbol equation is correct?

a)

2Na(s) + 2H2O(l) -> 2NaOH(l) + H2(g)

b)

2Na(s) + 2H2O(g) -> 2NaOH(aq) + H2(g)

c)

2Na(s) + 2H2O(l) -> 2NaOH(aq) + H2(g)

d)

2Na(s) + 2H2O(aq) -> 2NaOH(aq) + H2(g)

3.

Germanium, Ge is extracted from Germanium(IV) oxide by heating with hydrogen.

Balance the symbol equation below for the reaction by writing the missing coefficient.

GeO2 + _H2 -> Ge + 2H2O



(a)  

4.

Ethanol (CH3CH2OH) burns in oxygen (O2) to form carbon dioxide (CO2) and water (H2O).

Which one shows the balanced symbol equation for this reaction?

a)

CH3CH2OH + O2 -> CO2 + H2O

b)

CH3CH2OH + 2O2 -> 2CO2 + 3H2O

c)

CH3CH2OH + 3O2 -> 2CO2 + 3H2O

d)

CH3CH2OH + 5-> 2CO2 + 6H2O

5.

Which of the following shows a balanced symbol equation for the reaction of nitrogen (N2) and hydrogen (H2) forming ammonia (NH3)?

a)

N2 + H2 -> NH3

b)

2N2 + 3H2 -> 2NH3

c)

N2 + 2H2 -> 2NH3

d)

N2 + 3H2 -> 2NH3

6.

What is the relative formula mass (Mr) of Mg(OH)2?

(a)  

7.

Calculate the relative formula mass (Mr) of ammonium phosphate, (NH4)3PO4.

(Ar: N =14, H = 1, P = 31, O = 16)



(a)  

8.

Calculate the percentage composition by mass of nitrogen in ammonium phosphate, (NH4)3PO4.

(Ar: N =14, H = 1, P = 31, O = 16)

Round off your answer to two significant figures.

(Example 1: 14.6 is rounded off to 15)

(Example 2: 12.1 is rounded off to 12)

(a)  

9.

Calculate the percentage composition by mass of Aluminium, (Al) in Aluminium oxide, Al2O3?

(Ar: Al = 27, O = 16).

Round off your answer to two significant figures.

a)

26

b)

53

c)

54

d)

63

10.

Strontium carbonate, SrCO3 is a compound used in red fireworks display.

Strontium is the element responsible for the red colour.

Calculate the percentage by mass of Strontium (Sr) in Strontium carbonate (SrCO3)

Ar: Sr = 88, C = 12, O = 16

Round off your answer to two significant figures.

(Example 1: 14.6 is rounded off to 15)

(Example 2: 12.1 is rounded off to 12)

(a)