A 18.2 g sample of an unknown compound contains 0.7 g of oxygen. What is the percent by mass of oxygen in the compound?
What is .7/18.2?
To find the percent by mass of oxygen in the compound, you need to divide the mass of oxygen by the mass of the entire compound and then multiply the result by 100. Here's how you can calculate it step by step:
1. Determine the mass of the entire compound: In this case, the given mass of the unknown compound is 18.2 g.
2. Determine the mass of oxygen: The given mass of oxygen in the compound is 0.7 g.
3. Divide the mass of oxygen by the mass of the entire compound: Divide 0.7 g by 18.2 g to get the decimal fraction that represents the ratio of oxygen to the entire compound.
\[ 0.7 \, \text{g} / 18.2 \, \text{g} = 0.038 \]
4. Multiply the decimal fraction by 100 to find the percent: Multiply 0.038 by 100 to get the percent value.
\[ 0.038 \times 100 = 3.8 \]
The percent by mass of oxygen in the compound is 3.8%.