A sample of hydrated magnesium sulfate is analyzed to determine its formula
CHEMISTRY · Multi-part · A Level · Chemistry · Amount of substance · Amount of substance
Problem
A sample of hydrated magnesium sulfate is analyzed to determine its formula. A clean, dry crucible is loaded with 3.250 g of the hydrate. After heating to constant mass, the residue of anhydrous MgSO4 weighs 1.960 g.
(a) Calculate the number of moles of water lost during heating.
(b) Calculate the number of moles of anhydrous MgSO4 present after heating.
(c) Determine the integer value of x in the empirical formula MgSO4⋅xH2O for the original hydrate sample.
(d) Using your value of x, compute the percentage by mass of water in MgSO4⋅xH2O. Provide your final answer to three significant figures.