Chemistry 5070 · O Level · Physical and chemical changes

Physical and chemical changes — practice question

Hydrated sodium carbonate breaks down when it is heated in a Bunsen burner flame. Which equation represents this decomposition correctly?

  • A$2\text{Na}_2\text{CO}_3\cdot10\text{H}_2\text{O (s)} \rightarrow 4\text{Na (s)} + 2\text{CO}_2\text{(g)} + \text{O}_2\text{(g)} + 10\text{H}_2\text{O (g)}$
  • B$\text{Na}_2\text{CO}_3\cdot10\text{H}_2\text{O (s)} \rightarrow \text{Na}_2\text{CO}_3\text{(s)} + 10\text{H}_2\text{O (g)}$
  • C$\text{Na}_2\text{CO}_3\cdot10\text{H}_2\text{O (s)} \rightarrow \text{NaHCO}_3\text{(s)} + \text{NaOH (s)} + 9\text{H}_2\text{O (g)}$
  • D$\text{Na}_2\text{CO}_3\cdot10\text{H}_2\text{O (s)} \rightarrow \text{Na}_2\text{O (s)} + \text{CO}_2\text{(g)} + 10\text{H}_2\text{O (g)}$

Worked solution & mark scheme

This 1-mark question has a full step-by-step worked solution and mark scheme.

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI