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Introducing chemical reactions

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Question 23

A student heats a sample of copper powder in an open crucible. The copper reacts with oxygen gas from the air to produce copper(II) oxide:

\text{copper} + \text{oxygen} \rightarrow \text{copper(II) oxide}

The mass of the copper powder before heating is 12.70 g. After the reaction is complete, the mass of the copper(II) oxide formed is 15.90 g.

According to the law of conservation of mass, what mass of oxygen gas reacted with the copper?

$g3.20\text{ g}$

$g1.60\text{ g}$

$g15.90\text{ g}$

$g28.60\text{ g}$

Markscheme

Introducing chemical reactions Questions

GCSE
Chemistry
Introducing chemical reactions

55 exam-style questions on OCR GCSE Chemistry Introducing chemical reactions. Each one has a worked solution and a mark scheme showing where the marks go.

Introducing chemical reactions

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Introducing chemical reactions

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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

Question 23

A student heats a sample of copper powder in an open crucible. The copper reacts with oxygen gas from the air to produce copper(II) oxide:

\text{copper} + \text{oxygen} \rightarrow \text{copper(II) oxide}

The mass of the copper powder before heating is 12.70 g. After the reaction is complete, the mass of the copper(II) oxide formed is 15.90 g.

According to the law of conservation of mass, what mass of oxygen gas reacted with the copper?

$g3.20\text{ g}$

$g1.60\text{ g}$

$g15.90\text{ g}$

$g28.60\text{ g}$

Markscheme

Introducing chemical reactions Questions

GCSE
Chemistry
Introducing chemical reactions

55 exam-style questions on OCR GCSE Chemistry Introducing chemical reactions. Each one has a worked solution and a mark scheme showing where the marks go.