Answer
a) C: $57.82\%$ H: $6.07\%$ O: $19.26\%$ N: $16.86\%$
b) C: $76.86\%$ H: $12.90\%$ O: $10.24\%$
c) Co: $24.77\%$ Cl: $29.80\%$ H: $5.08\%$ O: $40.35\%$
Work Step by Step
Atomic weights (g/mol): $Co: 58.933,\ Cl:35.45,\ C: 12.011,\ H: 1.008,\ O: 15.999,\ N: 14.007$
Molar masses (g/mol): $C_8H_{10}N_2O_2: 166.18,\ C_{10}H_{20}O:156.26,\ CoCl_2\dot{}6\ H_2O: 237.93$
a) C: $8\times12.011/166.18\times100\%=57.82\%$
H: $10\times1.008/166.18\times100\%=6.07\%$
O: $2\times15.999/166.18\times100\%=19.26\%$
N: $2\times14.007/166.18\times100\%=16.86\%$
b) C: $10\times12.011/156.26\times100\%=76.86\%$
H: $20\times1.008/156.26\times100\%=12.90\%$
O: $15.999/156.26\times100\%=10.24\%$
c) Co: $58.933/237.93\times100\%=24.77\%$
Cl: $2\times35.45/237.93\times100\%=29.80\%$
H: $12\times1.008/237.93\times100\%=5.08\%$
O: $6\times15.999/237.93\times100\%=40.35\%$
