A sample of seawater has a strontium concentration of 57 ppm. What is the mass of strontium in grams in 1 liter of seawater, assuming the density of seawater is 1.025 g/mL?

• A. 0.060 grams
• B. 0.058 grams
• C. 0.057 grams
• D. 0.059 grams

Answer: (B)

Verified step by step guidance

1. Understand that ppm (parts per million) is a way to express very dilute concentrations of substances. 1 ppm means 1 part of solute per 1,000,000 parts of solution.
2. Convert the volume of seawater from liters to milliliters, since the density is given in g/mL. 1 liter is equivalent to 1000 milliliters.
3. Calculate the mass of 1 liter of seawater using the density. Use the formula: \( \text{mass} = \text{density} \times \text{volume} \). Substitute the given values: \( \text{mass} = 1.025 \text{ g/mL} \times 1000 \text{ mL} \).
4. Determine the mass of strontium in the seawater using the ppm concentration. Since 57 ppm means 57 grams of strontium per 1,000,000 grams of seawater, set up a proportion to find the mass of strontium in the calculated mass of seawater.
5. Solve the proportion to find the mass of strontium in grams. Use the formula: \( \text{mass of strontium} = \frac{57}{1,000,000} \times \text{mass of seawater} \).