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3 Quantitative chemistry

3 Quantitative chemistry

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Question 77

A student investigated the mass of magnesium oxide produced by the thermal decomposition of magnesium carbonate:

MgCO3(s)→MgO(s)+CO2(g) \text{MgCO}_3(\text{s}) \rightarrow \text{MgO}(\text{s}) + \text{CO}_2(\text{g}) MgCO3​(s)→MgO(s)+CO2​(g)

The table below shows the student's results:

Mass of magnesium carbonate (g)Mass of magnesium oxide (g): Trial 1Mass of magnesium oxide (g): Trial 2Mass of magnesium oxide (g): Trial 3Mean mass of magnesium oxide (g)
4.001.921.891.921.91
8.003.843.813.843.83
12.003.205.765.74ZZZ
16.007.677.637.657.65
a.

Identify the anomalous result in the table by stating the mass of magnesium carbonate and the trial number.

[1]
b.

Calculate the mean mass ZZZ of magnesium oxide produced from 12.00 g of magnesium carbonate. You should exclude the anomalous result from your calculation.

[2]
c.

Use your value of ZZZ to calculate the mass of magnesium oxide produced when 180.0 g of magnesium carbonate is heated.

[2]
Markscheme

3 Quantitative chemistry Questions

  1. GCSE
  2. /Chemistry
  3. /3 Quantitative chemistry

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