1.1. A student uses this apparatus to heat crystals of hydrated zinc sulfate and collect the liquid produced.

i) Describe a chemical test to show that the colourless liquid contains water.

 (2)

 ii) Describe a physical test to show the colourless liquid is pure water.

 (2)

1.2. The equation for the decomposition of hydrated zinc sulfate is 

ZnSO₄·7H₂O (s) → ZnSO₄ (s) + 7H₂O (l)

The student records these masses. 

• mass of boiling tube = 41.64 g

• mass of boiling tube + ZnSO₄·7H₂O = 54.46 g 

Calculate the maximum volume, in cm³, of pure water that could be produced.

 Give your answer to 1 decimal place.

 [1.00 cm³ of pure water has a mass of 1.00 g]

 [M_r of ZnSO₄·7H₂O = 287   M_r of H₂O = 18]

maximum volume of pure water = .............................. cm³

1.3. In an experiment using a different mass of ZnSO₄·7H₂O the maximum volume of pure water that could be produced is 8.5 cm³. 

The student collected the pure water and calculated the percentage yield to be 20.3%.

i) Calculate the volume, in cm³, of pure water collected.

 (1)

volume of pure water = .............................. cm³

 ii) Explain an improvement to the apparatus that would increase the percentage yield of pure water.

 (2)