A certain hydrate has the formula MgSO4 xH2O If a quantity of 54 2 g of compound heated in - Chemistry - States of Matter

Question

A certain hydrate has the formula MgSO4 xH2O If a quantity of 54 2
g of compound heated in an oven to drive off the water If the steam
generated exerts a pressure of 24 8atm in a 2 00L container at 120
Celsius, compute x

Vartika Jain · Accepted Answer

Dear Student,

Applying ideal gas equation
PV=nRTor, n=massMolar mass=mMSo, PV=mMRTor, m=PVMRTSince the gas is steam in this case, which is the gaseous form of water, therefore, M= 18 gmol-1P=24
8bar ≈ 24 8 atmV= 2LR=0
0821 Latmmol-1K-1T=120°C=120+273=393 KTherefore, m=24
8×2×180 0821×393=27
6 gMolecular weight of MgSO4=24+32+64=120 gand, 54
2 g of salt gives off 27
6 g of H2OSo, actual weight of salt= 54
2-27 6=26 6 gThis means 26
6 g of salt gives 27
6 g of H2OThen 120 g will give 27
626 6×120=124
5 g of H2Oor, Moles of H2O=124 518=6
9≈7 molSo, x=7 and the salt is MgSO4
7H2O

A certain hydrate has the formula MgSO4.xH2O. If a quantity of 54.2 g of compound heated in an oven to drive off the water. If the steam generated exerts a pressure of 24.8atm in a 2.00L container at 120 Celsius, compute x.