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Calculations involving masses

Calculations involving masses

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Question 100

A sample of green copper(II) carbonate is strongly heated in a crucible to decompose it into black copper(II) oxide and carbon dioxide gas:

CuCO3(s)→CuO(s)+CO2(g) \text{CuCO}_3(\text{s}) \rightarrow \text{CuO}(\text{s}) + \text{CO}_2(\text{g}) CuCO3​(s)→CuO(s)+CO2​(g)

The mass of copper(II) oxide solid remaining in the crucible is found to be 3.25 g, which is less than the calculated theoretical mass.

Which of the following is a likely reason for this lower actual mass?

A

Some of the solid was lost as dust or spat out of the crucible during heating.

B

The thermal decomposition of the copper(II) carbonate was incomplete.

C

The remaining copper(II) oxide absorbed water vapor from the air before weighing.

D

Carbon dioxide gas remained trapped inside the crucible.

Markscheme

Calculations involving masses Questions

  1. GCSE
  2. /Chemistry
  3. /Calculations involving masses

258 exam-style questions on Edexcel GCSE Chemistry Calculations involving masses. Each one has a worked solution and a mark scheme showing where the marks go.

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