Question

A percent composition problem:

A 1.836-g sample of coal contains 1.584 g of C. What is the percent (%) weight of carbon in this sample of coal?
A) 86.07%
B) 13.93%
C) 15.41%
D) 84.59%

Answer 1

The percent composition of carbon in the coal sample is calculated by dividing the mass of carbon (1.584 g) by the total mass of the sample (1.836 g) and then multiplying by 100, which results in 86.29%.

Step-by-step explanation:

To calculate the percent composition of carbon in the coal sample, you divide the mass of carbon by the total mass of the coal sample and then multiply by 100 to get a percentage. Here's a step-by-step calculation:

1. Find the mass of carbon in the sample: 1.584 g.
2. Find the total mass of the coal sample: 1.836 g.
3. Divide the mass of carbon by the total mass of the coal sample: 1.584 g ÷ 1.836 g = 0.8629.
4. Multiply by 100 to convert to a percentage: 0.8629 × 100 = 86.29%.

The correct answer for the weight percent of carbon in the coal sample is 86.29%, rounded here as 86.29% to match the available answer choices, the nearest of which is A) 86.07%.