A compound is made of hydrogen and oxygen.

What is the percent oxygen by mass if a sample contains 2.0 g of hydrogen and 33.0 g of oxygen?

A. [tex]$94.3 \%$[/tex]
B. [tex]$5.71 \%$[/tex]
C. [tex]$0.0571 \%$[/tex]
D. [tex]$0.943 \%$[/tex]



Answer :

To determine the percent oxygen by mass in a compound that contains 2.0 grams of hydrogen and 33.0 grams of oxygen, follow these steps:

1. Calculate the total mass of the compound:
- The mass of hydrogen = 2.0 grams
- The mass of oxygen = 33.0 grams
- Total mass = mass of hydrogen + mass of oxygen
- Total mass = 2.0 g + 33.0 g = 35.0 grams

2. Calculate the percent oxygen by mass:
- Percent mass of oxygen = (mass of oxygen / total mass) 100
- Percent mass of oxygen = (33.0 g / 35.0 g)
100

3. Perform the division and multiplication:
- Mass ratio = 33.0 / 35.0 ≈ 0.942857
- Percent mass of oxygen = 0.942857 * 100 ≈ 94.3%

So, the percent oxygen by mass in the compound is approximately [tex]\( 94.3\% \)[/tex].

Therefore, the correct answer is:
[tex]\[ 94.3 \% \][/tex]