Question #2f5be

1 Answer
Jun 7, 2016

x =3

Explanation:

The reaction is:

MgCO_3*xH_2OtoMgCO_3+xH_2O

The masses involved can be identified:

1.25g to 0.759g+0.491g (the mass of water being the balancing figure from the information given)

If we determine the relative formula mass for the various components in the above reaction, we can determine the number of moles involved:

MgCO_3=24.305+12.011+(15.999times3)=84.313
H_2O=(1.008*2)+15.999=18.015

Hence the number of moles on the right hand side of the equation can be determined:
MgCO_3=0.759/84.313=9.00times10^-3"moles"

H_2O=0.491/18.015=0.02725 "moles"

The ratio of H_2O to MgCO_3=0.02725/(9.00times 10^-3)=3.028
Hence x= 3