Question

what is the percent composition of hydrogen in a compound if the mass of the initial compound is 276 grams and the mass of collected hydrogen after decomposition is 41.4 grams?

a. 6.6%
b. 10.0%
c. 15.0%
d. 21.2%

Explanation:

Step1: Recall percent - composition formula

Percent composition of an element $=\frac{\text{Mass of element}}{\text{Mass of compound}}\times100\%$

Step2: Substitute given values

Here, mass of hydrogen $ = 41.4$ grams and mass of compound $=276$ grams. So, $\frac{41.4}{276}\times100\%$

Step3: Calculate the result

$\frac{41.4}{276}=0.15$, and $0.15\times100\% = 15.0\%$

Answer:

C. 15.0%