This question is about hydrated ammonium iron(III) sulfate. 

A student needs to find the value of x in the formula (NH₄)₂SO₄.Fe₂(SO₄)₃.xH₂O.

The apparatus used by the student is below. 

The hydrated solid decomposed when heated.

The equation for the reaction is 

(NH₄)₂SO₄.Fe₂(SO₄)₃.xH₂O → (NH₄)₂SO₄.Fe₂(SO₄)₃ + xH₂O

The table below shows the student's results. 

Calculate the mass of water produced. 

Calculate the mass of (NH₄)₂SO₄.Fe₂(SO₄)₃ produced.

Calculate the value of x. 

The molar mass of (NH₄)₂SO₄.Fe₂(SO₄)₃ is 532, and the molar mass of water is 18.

Give your answer to the nearest whole number. 

This question is about a hydrated sample of calcium sulfate CaSO₄.xH₂O.

A student takes gently heats the hydrated sample of calcium sulfate to obtain water. 

The table below shows the student's results. 

Calculate the mass of CaSO₄ produced. 

Calculate the mass of water produced. 

Calculate the number of moles of CaSO₄ and hence determine the value of x.

(You may need a periodic table)

This question is about hydrated magnesium sulfate, MgSO₄.xH₂O.

A sample of hydrated magnesium sulfate is found to have 48.9% magnesium sulfate. 

Calculate the percentage of water in the hydrated sample.

Calculate the value of x.