Water of Crystallisation & Finding Formulae Experimentally - exam practice
Water of Crystallisation & Finding Formulae Experimentally
Question 1 of 3
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.