Chemistry => Solutions => Dilution
A solution is a mixture of two or more substances. In this case, we have a solution of acid in water. For dilutions we can apply the following equation:
[tex]C_1V_1=C_2V_2[/tex]Where,
C1 is the initial concentration, 45%
V1 is the initial volume of the solution, 70mL
C2 is the final concentration, 30%
V2 is the final volume of the solution, unknown
Now, we clear V2 and replace the known data:
[tex]\begin{gathered} V_2=\frac{C_1V_1}{C_2} \\ \\ V_2=\frac{45\%\times70mL}{30\%} \\ \\ V_2=105mL \end{gathered}[/tex]The final volume of the solution will be 105 mL. The water should be added will be:
[tex]\begin{gathered} H_2O=V_2-V_1 \\ \\ H_2O=105mL-70mL \\ \\ H_2O=35mL \end{gathered}[/tex]Answer: To dilute the solution from 45% to 30%, should be added 35 mL of water.
