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Chemical Equation and stoichiometry

Total questions: 11

Worksheet time: 22mins

Name
Class
Date
1.

The oxidation number for oxygen in H3O+ is

a)

zero.

b)

a positive number.

c)

a negative number.

d)

the charge of the ion

2.

Aluminium, Al reacts with iron (II) oxide, FeO to produce iron, Fe and aluminum oxide, Al2O3. the balanced equation for the reaction is

a)

2Al(s) + FeO(s) → Fe(s) + Al2O3(s)

b)

Al(s) + 2FeO(s) → Fe(s) + 2Al2O3(s)

c)

3Al(s) + 3FeO(s) → 3Fe(s) + Al2O3(s)

d)

2Al(s) + 3FeO(s) → 3Fe(s) + Al2O3(s)

3.

The following reaction shows the neutralisation of calcium hydroxide solution, Ca(OH)2 by hydrochloric acid, HCl;


Ca(OH)2(aq) + 2HCl (aq) → CaCl2(aq) + 2H2O(l)


Calculate the number of mole of HCl needed to produce 0.50 mol CaCl2.

a)

0.50

b)

0.75

c)

1.00

d)

2.00

4.

Redox reaction involves reduction and oxidation processes. In the oxidation process

a)

the species gains oxygen atom.

b)

the species gains hydrogen atom.

c)

the species gains one or more electron(s).

d)

the oxidation number of element decreases.

5.

What is the coefficient of Fe3O4 when the following equation is correctly balanced?

Al + Fe3O4 → Al2O3 + Fe

a)

1

b)

2

c)

3

d)

4

6.

What is the concentration of an aqueous solution of H2SO4 if 25.00 mL of the solution is neutralised by 15.00 mL of 0.75 M NaOH?

a)

0.2250 M

b)

0.2115 M

c)

0.1770 M

d)

0.0225 M

7.

Potassium chlorate, KClO3 decomposes upon heating to form oxygen gas.


2KClO 3→ 2KCl + 3O2


What is the theoretical yield of oxygen gas from the decomposition of 12.25 g of potassium chlorate?

a)

4.08 g

b)

4.68 g

c)

4.80 g

d)

4.88 g

8.

The oxidation number of nitrogen in N2O and N2F4 are respectively

a)

-2 and -3

b)

-2 and +2

c)

+1 and +2

d)

+1 and -3

9.

Identify the reducing agent of this redox equation


2NO2 (g) + 7H2 (g) → 2NH3 (g) + 4H2O (g)

a)

H2

b)

NH3

c)

NO2

d)

H2O

10.

Antimony can react with chlorine gas to give antimony trichloride.


__Sb (s) + __Cl2 (g) → __SbCl3

a)

1,1,1

b)

4,6,4

c)

1,3,2

d)

2,3,2

11.

The oxidation number of Vanadium atom in (NH4)3VO4 is

a)

+3

b)

+4

c)

+5

d)

+7