Question

"A chemistry student attempted to make a 0.2000 M solution of NaCl using a 100.0 mL volumetric flask. She added exactly 100.0 mL of water to the flask, then added 0.02000 mol of NaCl, and found that the total volume in the flask was above the 100.0 mL mark. What was the concentration of the solution?"

Answer 1

Answer:

The answer is : a little less than 0.200 M

Explanation:

The molarity of a solution is the number of moles of solute in 1 liter of solution.

In this problem, the chemist student added 0.0200 mol to 100 ml of water. In order to calculate the molarity, we divide the number of moles of NaCl into the total volume and then we multiply by 1000 to obtain the moles per liter:

M = $\frac{0.0200 mol}{100 ml} x \frac{1000 ml}{1 L} = \frac{0.200 mol}{L}$

The total volume of the solution was above 100.0 ml, so the solution was a little bit more diluted than 0.200 M.

Answer 2

Explanation:

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