Question #2f5be

1 Answer
Jun 7, 2016

x=3

Explanation:

The reaction is:

MgCO3xH2OMgCO3+xH2O

The masses involved can be identified:

1.25g0.759g+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:

MgCO3=24.305+12.011+(15.999×3)=84.313
H2O=(1.0082)+15.999=18.015

Hence the number of moles on the right hand side of the equation can be determined:
MgCO3=0.75984.313=9.00×103moles

H2O=0.49118.015=0.02725moles

The ratio of H2O to MgCO3=0.027259.00×103=3.028
Hence x=3