Question

A solution is prepared by pipetting 20.00 mL of a 1.00 x 10-3 M NaCl solution into a 250.0 mL volumetric flask. The flask is diluted to the mark with deionized water. Calculate the concentration of the newly prepared solution.

Answer 1

The concentration of the newly prepared solution is 8 * 10^-5 M

Step-by-step explanation:

The most common way to solve this problem is to use the following formula

c1*V1 = c2*V2

with c1 = 1 * 10^-3 M

with V1 = 20 mL = 0.02 L

with c2 = TO BE DETERMINED

with V2 = 250 mL = O.250 L

10^-3 * 0.02 L = c2 * 0.250L

0.00002 = c2 * 0.250L

c2 = 0.00002 / 0.250 L

c2 = 0.00008 M = 8 * 10^-5 M

The concentration of the newly prepared solution is 8 * 10^-5 M