Question

how many grams of solute are needed to make 354. ml of \\(1.61 \times 10^{-2}\\) m potassium sulfate? be sure your answer has the correct number of significant figures.

Explanation:

Calculate moles of potassium sulfate

$$ n = M \times V = (1.61 \times 10^{-2}\text{ mol/L}) \times (0.354\text{ L}) = 5.6994 \times 10^{-3}\text{ mol} $$

Determine molar mass of potassium sulfate

$$ \text{Molar Mass of }\text{K}_2\text{SO}_4 = 2(39.10) + 32.06 + 4(16.00) = 174.26\text{ g/mol} $$

Calculate mass of solute in grams

$$ \text{mass} = 5.6994 \times 10^{-3}\text{ mol} \times 174.26\text{ g/mol} = 0.99318\text{ g} \approx 0.993\text{ g} $$

Answer:

How many grams of solute are needed to make 354. mL of \(1.61 \times 10^{-2}\) M potassium sulfate? Be sure your answer has the correct number of significant figures.

<blank>0.993</blank> g solute