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Calculations involving masses

Calculations involving masses

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Question 106

Hydrated sodium carbonate has the formula Na2CO3⋅10H2O\text{Na}_2\text{CO}_3 \cdot 10\text{H}_2\text{O}Na2​CO3​⋅10H2​O.

The formula tells us that each mole of hydrated sodium carbonate contains 10 moles of water.

A sample of Na2CO3⋅10H2O\text{Na}_2\text{CO}_3 \cdot 10\text{H}_2\text{O}Na2​CO3​⋅10H2​O was heated gently until all the water was removed to form anhydrous sodium carbonate, Na2CO3\text{Na}_2\text{CO}_3Na2​CO3​.

Na2CO3⋅10H2O→Na2CO3+10H2O \text{Na}_2\text{CO}_3 \cdot 10\text{H}_2\text{O} \rightarrow \text{Na}_2\text{CO}_3 + 10\text{H}_2\text{O} Na2​CO3​⋅10H2​O→Na2​CO3​+10H2​O

The mass of water formed was 27.0 g.

Calculate the mass of hydrated sodium carbonate that was heated. (relative atomic masses: H=1.0\text{H} = 1.0H=1.0, O=16.0\text{O} = 16.0O=16.0; relative formula mass: Na2CO3⋅10H2O=286.0\text{Na}_2\text{CO}_3 \cdot 10\text{H}_2\text{O} = 286.0Na2​CO3​⋅10H2​O=286.0)

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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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