Question

question 3
1 pts
calculate the percent composition of hydrogen and carbon in a 16.05 gram
sample containing 4.04 grams of hydrogen and 12.01 grams of carbon.
30.6%, 69.4%
25.2%, 74.8%
33.3%, 66.7%
4.0%, 12%
question 4
1 pts
a sample of a liquid with a mass of 8.657 grams was decomposed into its
elements to give 5.217 grams of carbon, 0.9620 grams of hydrogen, and 2.478
grams of oxygen. what is the percentage composition of each element for this
compound?
c: 43.64%, h: 10.21%, o: 46.15%
c: 12.01%, h: 10.10%, o: 77.89%
c: 60.26%, h: 11.11%, o: 28.62%
c: 81.54%, h: 3.69%, o: 14.77%

Explanation:

Step1: Calculate the percentage of hydrogen

The formula for percentage composition is \(\text{Percentage}=\frac{\text{Mass of element}}{\text{Mass of sample}}\times100\%\).
For hydrogen, \(\text{Mass of element} = 4.04\space g\), \(\text{Mass of sample}=16.05\space g\)
\(\text{Percentage of }H=\frac{4.04}{16.05}\times 100\%\)
\(\frac{4.04}{16.05}\times100\%=\frac{404}{16.05}\% \approx 25.2\%\)

Step2: Calculate the percentage of carbon

For carbon, \(\text{Mass of element} = 12.01\space g\), \(\text{Mass of sample}=16.05\space g\)
\(\text{Percentage of }C=\frac{12.01}{16.05}\times 100\%\)
\(\frac{12.01}{16.05}\times100\%=\frac{1201}{16.05}\% \approx 74.8\%\)

Answer:

25.2%, 74.8%