Final answer:
To find the mass of copper in a 38.0 g sample of Cu2S composed of 79.852% copper, multiply the total mass by the percentage (0.79852), yielding approximately 30.34 g. However, the closest provided option is 30.28 g.
Step-by-step explanation:
The question pertains to the determination of the mass of copper in a sample of copper sulfide (Cu2S) given the percentage of copper in the compound. To find the mass of copper, we multiply the total mass of the compound by the percentage of copper. The mass of copper in a 38.0 g sample of Cu2S, which is 79.852% copper, can be calculated as follows:
- Convert the percentage to a decimal: 79.852% = 0.79852.
- Multiply this decimal by the total mass of the Cu2S sample to find the mass of copper:
38.0 g × 0.79852 = 30.34 g.
However, the closest answer from the provided options to our calculation is 30.28 g, which might suggest a rounding difference in the percentage value or the final calculation in the options provided.