question_answer 53)

  What is the mass per cent of carbon in carbon dioxide? (a) 0.034%                           (b) 27.27% (c) 3.4%                                (d) 28.7%

Answer:

  (b) \[\text{ }\!\!%\!\!\text{ }\,\text{Carbon=}\frac{\text{Mass}\,\text{of}\,\text{Carbon}}{\text{Molar}\,\text{mass}\,\text{of}\,\text{C}{{\text{O}}_{\text{2}}}}\text{ }\!\!\times\!\!\text{ 100}\] \[=\frac{12}{44}\times 100=27.27\]