Calculate the mass/volume percent (m/v) for the solute in each of the following:
a. 75 g of Na₂SO₄ in 250 mL of Na₂SO₄ solution

Verified step by step guidance

1. Step 1: Understand the formula for mass/volume percent (m/v). It is defined as: $\frac{\mathrm{mass}\left(g\right)}{\mathrm{volume}\left(\mathrm{mL}\right)}\times 100$. This formula expresses the concentration of a solute in a solution as a percentage.
2. Step 2: Identify the given values in the problem. The mass of the solute (Na₂SO₄) is 75 g, and the volume of the solution is 250 mL.
3. Step 3: Substitute the given values into the formula. Replace 'mass' with 75 g and 'volume' with 250 mL in the formula: $\frac{75}{250}\times 100$.
4. Step 4: Perform the division in the numerator to calculate the fraction. Divide 75 by 250 to get the decimal value.
5. Step 5: Multiply the result from Step 4 by 100 to convert the decimal into a percentage. This will give you the mass/volume percent (m/v) of Na₂SO₄ in the solution.

Key Concepts

Mass/Volume Percent (m/v)

Mass/volume percent (m/v) is a concentration measurement that expresses the mass of a solute in grams per 100 mL of solution. It is calculated using the formula: (mass of solute in grams / volume of solution in mL) × 100. This metric is particularly useful in chemistry for quantifying the concentration of solutions, allowing for easy comparisons and calculations.

Solute and Solution

In a solution, the solute is the substance that is dissolved, while the solvent is the substance that does the dissolving. In this case, Na₂SO₄ is the solute, and the solution is the mixture of Na₂SO₄ and the solvent (usually water). Understanding the roles of solute and solvent is crucial for calculating concentrations and performing related chemical calculations.

Units of Measurement

Units of measurement are essential in scientific calculations to ensure accuracy and consistency. In this context, grams (g) measure mass, and milliliters (mL) measure volume. Being familiar with these units and how to convert between them is vital for correctly calculating mass/volume percent and interpreting results in chemistry.