1.1. The gas burned in a Bunsen burner is methane.

The equation for the complete combustion of methane is

CH₄ (g) + 2O₂ (g) → CO₂ (g) + 2H₂O (g)

Calculate the mass of oxygen required to react with 32 g of methane.

  [M_r of methane = 16]

 mass of oxygen = .............................. g

1.2. The diagram shows methane burning in air. It also shows how the two gases formed are collected and tested.

 i) Explain why water collects in the U-tube.

 (2)

 ii) Describe how anhydrous copper(II) sulfate is used to test for water.

 (2)

 iii) Explain the change in the appearance of the limewater.

 (3)