Question

alculate the percent by mass (percent composition) of hydrogen in methane (CH4). Round your answer to the nearest whole number.

Answer 1

Answer:

25

Explanation:

In one mole of methane $(CH_{4})$ there are 4 moles of hydrogen and one mole of carbon atom.

Mass of 1 mole of hydrogen atom = 1 g

Mass of 4 moles of hydrogen atom = 4 g

Mass of 1 mole of carbon atom = 12 g

Mass of 1 mole of methane = 12+4 = 16 g

Mass percent of hydrogen in methane = $\frac{mass\ of\ 4\ moles\ of\ hydrogen\ atom}{mass\ of\ 1\ mole\ of\ methane}$

$=\frac{4}{16}\times100=25$

Answer 2

Answer:25%

Explanation:

The total molecular mass of methane (CH4) = 12+4 =16

Hydrogen has a total mass of 4 out of the 16. Now to calculate the percentage of hydrogen there, we have (4/16) x 100 = 25