Questions: A chemistry student needs 75.0 g of 2-ethyltoluene for an experiment. She has available 0.50 kg of a 40.5% w / w solution of 2-ethyltoluene in acetone. Calculate the mass of solution the student should use. If there's not enough solution, press the "No solution" button. Round your answer to 3 significant digits.

Solution Steps

The student needs 75.0 g of 2-ethyltoluene.

The available solution is 0.50 kg (or 500 g) with a concentration of 40.5% w/w of 2-ethyltoluene.

The mass of 2-ethyltoluene in the solution is: \[ \text{Mass of 2-ethyltoluene} = 0.405 \times 500 \, \text{g} = 202.5 \, \text{g} \]

Since 202.5 g of 2-ethyltoluene is available, which is more than the required 75.0 g, there is enough solution.

To find the mass of the solution that contains 75.0 g of 2-ethyltoluene, use the proportion: \[ \frac{75.0 \, \text{g}}{0.405} = 185.1852 \, \text{g} \]

The mass of the solution needed, rounded to 3 significant digits, is: \[ 185 \, \text{g} \]

Final Answer