Question

Determine the volume of distilled water that should be added to 20.0 mL of 12.0 M HCl(aq) in order to prepare a 0.500 M HCl(aq) solution.

Answer 1

`V_(H_2O)=460 mL`

Step-by-step explanation:

Hello!

In this case, in a dilution process, water is added to a solute in order to decrease its concentration but increase the volume of the solution. It means that if we have 20.0 mL of a 12.0-M solution of HCl and we want a 0.500-M solution, we need to apply the following formula considering that the moles remain unchanged:

`M_1V_1=M_2V_2`

Thus, solving for the final volume is:

`V_2=(M_1V_1)/(M_2)`

So plugging in the values we obtain:

`V_2=(12.0M*20.0mL)/(0.500M)\\\\V_2=480 mL`

Now, since the initial volume of acid was 20.0 mL and the final volume is 480 mL, the added volume of distilled water is:

`V_(H_2O)=480-20=460 mL`

Best regards!