Q. 0.5 g of hydrocarbon gave 0.9 g water on combustion. The percentage of carbon hydrocarbon is
A) 60.6
B) $28.8$
C) $80.0$
D) $68.6$
Explanation
(c)
$\%\ of\ H = \frac{2}{18} \times \frac{weight\ of\ H_{2}O}{weight\ of\ organic\ compound\ } \times 100$
$= \frac{2}{18} \times \frac{0.9}{0.5} \times 100 = 20\%$
$\therefore$ The percentage of carbon $= 100 - 20 = 80\ \%$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.