Question

To how much water should 50mL of 12M hydrochloric acid be added to produce a 4M solution?

Answer 1

50 mL of 12M HCl should be added into 100 mL of water to produce a 4M solution.

Step-by-step explanation:

According to law of dilution-

`C_(1)V_(1)=C_(2)V_(2)`

where
`C_(1),C_(2),V_(1)` and
`V_(2)` are initial concentration, final concentration, initial volume and final volume respectively.

Here,
`C_(1)=12M` ,
`C_(2)=4M` ,
`V_(1)=50mL`

So,
`V_(2)=(C_(1)V_(1))/(C_(2))` =
`((12M)* (50mL))/((4M))` = 150 mL

Hence, final volume of HCl solution should be 150 mL.

So, volume of water needed = (150-50) mL = 100 mL

Therefore 50 mL of 12M HCl should be added into 100 mL of water to produce a 4M solution.