10 mL of gaseous hydrocarbon on combustion gives 40 mL of CO 2 g and 50 mL of water vapour. Total number of carbon and hydrogen atoms in the hydrocarbon is _______.

Step-by-step solution

The combustion reaction can be represented as C x H y + x + y 4 O 2 → xCO 2 + yH 2 O At STP, 1 mole of any gas occupies 22 . 4 L 10 mL of hydrocarbon, 50 mL of water and 40 mL of carbon dioxide corresponds to 0 . 45 , 2 . 23 , and 1 . 79 moles respectively. Hence, the combustion of 1 mole of hydrocarbon will produce 5 moles of water and 4 moles of carbon dioxide. Thus, the molecular formula contains 4 carbon atoms and 10 hydrogen atoms. The hydrocarbon is C 4 H 10 and the combustion reaction is C 4 H 10 + 6 . 5 O 2