Question

one of the ways to make 550 ml of a 0.077 m solution of sodium chloride using a 0.85 m stock solution, is to mix: 60.7 ml of the stock solution and 489 ml of water. 0.077 mol of sodium chloride and 550 ml of water. 50 ml of the stock solution and 500 ml of water. 50 ml of the stock solution and 550 ml of water.

Explanation:

Step1: Recall dilution formula

The dilution formula is \( M_1V_1 = M_2V_2 \), where \( M_1 \) is the molarity of the stock solution, \( V_1 \) is the volume of the stock solution, \( M_2 \) is the molarity of the diluted solution, and \( V_2 \) is the volume of the diluted solution.

Step2: Identify known values

We know \( M_1 = 0.85 \, M \), \( M_2 = 0.077 \, M \), and \( V_2 = 550 \, mL \). We need to find \( V_1 \).

Step3: Solve for \( V_1 \)

Rearrange the dilution formula to solve for \( V_1 \): \( V_1=\frac{M_2V_2}{M_1} \)
Substitute the known values: \( V_1 = \frac{0.077 \, M\times550 \, mL}{0.85 \, M} \)
Calculate the numerator: \( 0.077\times550 = 42.35 \)
Then divide by 0.85: \( V_1=\frac{42.35}{0.85}\approx60.7 \, mL \)

Step4: Calculate volume of water

The total volume of the diluted solution is 550 mL. So the volume of water is \( 550 \, mL - 60.7 \, mL = 489.3 \, mL\approx489 \, mL \)

Answer:

60.7 mL of the stock solution and 489 mL of water.