Question

A student pipets 10 ml of a 0.0693 m solution of kbr into a 500 ml volumetric flask and dilutes to the mark. what is the concentration of the resulting solution?

Answer 1

The initial concentration of solution is 0.0693 M. The volume of solution taken is 10 mL and it is diluted to a final volume of 500 mL.

According to dilution law, the product of initial concentration and volume is equal to the product of final concentration and volume as follows:

$C_{1}V_{1}=C_{2}V_{2}$

Here, $C_{1}$ is initial concentration, $C_{2}$ is final concentration, $V_{1}$ is initial volume and $V_{2}$ is final volume.

Rearranging to calculate final concentration,

$C_{2}=\frac{C_{1}\times V_{1}}{V_{2}}$

Putting the values,

$C_{2}=\frac{0.0693 M\times 10 mL}{500 mL}=0.001386 M$

Therefore, concentration of the resulting solution is 0.001386 M.