Chemistry for Cambridge International AS & A Level Coursebook with Digital Access (2 Years)>Chapter 3 - Atoms, Molecules and Stoichiometry>Question>Q 8

EASY

AS and A Level

IMPORTANT

Earn 100

Sodium reacts with excess oxygen to form sodium peroxide, ${Na}_{2} O_{2}$ .

$2 Na + O_{2} \to {Na}_{2} O_{2}$

Calculate the maximum mass of sodium peroxide formed when $4.60 g$ of sodium is burnt in excess oxygen. ( $A_{r}$ values: $Na = 23.0, O = 16.0$ ).

Important Questions on Atoms, Molecules and Stoichiometry

EASY

AS and A Level

IMPORTANT

Chemistry for Cambridge International AS & A Level Coursebook with Digital Access (2 Years)>Chapter 3 - Atoms, Molecules and Stoichiometry>Question>Q 8

Tin(IV) oxide is reduced to tin by carbon. Carbon monoxide is also formed.

${SnO}_{2} + 2 C \to Sn + 2 CO$

Calculate the mass of carbon that exactly reacts with $14.0 g$ of tin(IV) oxide. Give your answer to $3$ significant figures.

( $A_{r}$ values: $C = 12.0, O = 16.0, Sn = 118.7$ ).

EASY

AS and A Level

IMPORTANT

Chemistry for Cambridge International AS & A Level Coursebook with Digital Access (2 Years)>Chapter 3 - Atoms, Molecules and Stoichiometry>Question>Q 9

56.2 g

of silicon,

Si

, reacts exactly with

284.0 g

of chlorine,

{Cl}_{2}

, to form

340.2 g

of silicon(IV) chloride,

{SiCl}_{4}

. Use this information to calculate the stoichiometry of the reaction. (

A_{r}

values:

Cl = 35.5, Si = 28.1

).

EASY

AS and A Level

IMPORTANT

Chemistry for Cambridge International AS & A Level Coursebook with Digital Access (2 Years)>Chapter 3 - Atoms, Molecules and Stoichiometry>Question>Q 10

Calculate the percentage by mass of carbon in ethanol,

C_{2} H_{5} OH

. (

A_{r}

values:

C = 12.0, H = 1.0, O = 16.0

).

EASY

AS and A Level

IMPORTANT

Chemistry for Cambridge International AS & A Level Coursebook with Digital Access (2 Years)>Chapter 3 - Atoms, Molecules and Stoichiometry>Question>Q 11

Deduce the empirical formula of hydrazine,

N_{2} H_{4}

.

EASY

AS and A Level

IMPORTANT

Chemistry for Cambridge International AS & A Level Coursebook with Digital Access (2 Years)>Chapter 3 - Atoms, Molecules and Stoichiometry>Question>Q 11

Deduce the empirical formula of octane,

C_{8} H_{18}

.

EASY

AS and A Level

IMPORTANT

Chemistry for Cambridge International AS & A Level Coursebook with Digital Access (2 Years)>Chapter 3 - Atoms, Molecules and Stoichiometry>Question>Q 11

Deduce the empirical formula of benzene,

C_{6} H_{6}

.

EASY

AS and A Level

IMPORTANT

Chemistry for Cambridge International AS & A Level Coursebook with Digital Access (2 Years)>Chapter 3 - Atoms, Molecules and Stoichiometry>Question>Q 11

Deduce the empirical formula of ammonia,

{NH}_{3}

.

EASY

AS and A Level

IMPORTANT

Chemistry for Cambridge International AS & A Level Coursebook with Digital Access (2 Years)>Chapter 3 - Atoms, Molecules and Stoichiometry>Question>Q 12

The composition by mass of a hydrocarbon is

10 %

hydrogen and

90 %

carbon. Deduce the empirical formula of this hydrocarbon. (

A_{r}

values:

C = 12.0, H = 1.0

).