A chemist prepares a solution of sodium chloride (NaCl) by measuring out 49. umol of sodium chloride into a 250. mL volumetric flask and filling the flask to the mark with water.

Question

Calculate the concentration in mmol/L of the chemist's sodium chloride solution. Be sure your answer has the correct number of significant digits.

Answer 1

First, we need to convert the given amount of NaCl from micromoles to millimoles:

49. umol x (1 mmol / 1000 umol) = 0.049 mmol

Next, we need to calculate the concentration in mmol/L:

Concentration (mmol/L) = (0.049 mmol) / (250 mL / 1000) = 0.196 mmol/L

Therefore, the concentration of the chemist's sodium chloride solution is 0.196 mmol/L.