A gaseous hydrogen and carbon containing compound is decomposed and found to contain 85.63% c and 14.37% h by mass. the mass of 258 ml of the gas, measured at stp, was found to be 0.646 g .
a) Approximately 10 g/mol
b) Approximately 20 g/mol
c) Approximately 30 g/mol
d) Approximately 40 g/mol