An alloy used in aerospace applications contains 15.0 g of titanium in a 120.0 g sample. What is the mass percent of titanium in the alloy?

• A. 8.0%
• B. 15.0%
• C. 12.5%
• D. 20.0%

Answer: (C)

Verified step by step guidance

1. Identify the given quantities: the mass of titanium (solute) is 15.0 g, and the total mass of the alloy (solution) is 120.0 g.
2. Recall the formula for mass percent, which expresses the mass of the solute as a percentage of the total mass: \(\text{Mass percent} = \left( \frac{\text{mass of solute}}{\text{total mass of solution}} \right) \times 100\%\).
3. Substitute the given values into the formula: \(\text{Mass percent of titanium} = \left( \frac{15.0\,\text{g}}{120.0\,\text{g}} \right) \times 100\%\).
4. Perform the division inside the parentheses to find the fraction of titanium in the alloy (do not calculate the final number here, just set up the expression).
5. Multiply the resulting fraction by 100 to convert it to a percentage, which will give the mass percent of titanium in the alloy.