Question

If 1.8 L of water is added to 2.5L of a 7.0 M KOH solution, what is the molarity of the new solution

Answer 1

Answer : The molarity of the new solution is, 4.069 M

Solution : Given,

Molarity of KOH solution = 4 M

Volume of KOH solution = 2.5 L

Volume of water added = 1.8 L

First we have to calculate the volume of new solution.

Volume of new solution = volume of KOH solution + volume of water added

Volume of new solution = 2.5 L + 1.8 L = 4.3 L

Now we have to calculate the molarity of the new solution.

Formula used :

`M_1V_1=M_2V_2`

where,

`M_1` = molarity of KOH solution

`M_2` = molarity of new solution

`V_1` = volume of KOH solution

`V_2` = volume of new solution

Now put all the given values in the above formula, we get the molarity of the new solution.

`(7M)* (2.5L)=M_2* (4.3L)`

`M_2=4.069M`

Therefore, the molarity of the new solution is, 4.069 M