Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 6 - Using Moles>Q>Q 7

HARD

Upper Secondary: IGCSE

IMPORTANT

Earn 100

An oxide of phosphorus has an $M_{r}$ value of $220$ . It is $56.4 %$ phosphorus. Find its molecular formula.

Important Questions on Using Moles

EASY

Upper Secondary: IGCSE

IMPORTANT

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 6 - Using Moles>Q>Q 1

Define the term

%

yield.

EASY

Upper Secondary: IGCSE

IMPORTANT

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 6 - Using Moles>Q>Q 1

Define the term

%

purity.

HARD

Upper Secondary: IGCSE

IMPORTANT

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 6 - Using Moles>Q>Q 2

100 g

of aspirin was obtained from

100 g

of salicylic acid. What was the

%

yieId?

HARD

Upper Secondary: IGCSE

IMPORTANT

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 6 - Using Moles>Q>Q 3

17 kg

of aluminium was produced from

51 kg

of aluminium oxide

({Al}_{2} O_{3})

by electrolysis. What was the percentage yield?

[A_{r} : Al = 27, O = 16]

EASY

Upper Secondary: IGCSE

IMPORTANT

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 6 - Using Moles>Q>Q 4

Some seawater is evaporated. The sea salt obtained is found to be

86 %

sodium chloride. How much sodium chloride could be obtained from

200 g

of this salt?

HARD

Upper Secondary: IGCSE

IMPORTANT

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 6 - Using Moles>Q>Q 5

A

5.0 g

sample of dry ice (solid carbon oxide) turned into

2400 {Cm}^{3}

of carbon dioxide gas at rtp. What was the percentage purity of the dry ice?

[M_{r} of {CO}_{2} = 44]

EASY

Upper Secondary: IGCSE

IMPORTANT

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 6 - Using Moles>Checkup on Chapter 6>Q 1

Iron is formed by reducing iron (III) oxide using the gas carbon monoxide. The reaction is:

${Fe}_{2} O_{3} (s) + 3 CO (g) \to 2 Fe (s) + 3 {CO}_{2} (g)$

Write a word equation for the reaction.

EASY

Upper Secondary: IGCSE

IMPORTANT

Complete Chemistry for Cambridge IGCSE® Second Edition>Chapter 6 - Using Moles>Checkup on Chapter 6>Q 1

Iron is formed by reducing iron (III) oxide using the gas carbon monoxide. The reaction is:

${Fe}_{2} O_{3} (s) + 3 CO (g) \to 2 Fe (s) + 3 {CO}_{2} (g)$

What is the formula mass of iron (IlI) oxide? $(A_{r} : Fe = 56, O = 16)$