Question

What is the concentration of a Ca(OH)2 solution if 15.0 ml of 0.750 M H3PO4 solution is required to completely neutralize 20.0 ml of the Ca(OH)2 solution?

Answer 1

15.0
+0.750
Answer (600

Answer 2

Answer: The concentration of
`Ca(OH)_2` comes out to be 0.843 M.

Step-by-step explanation:

To calculate the concentration of acid, we use the equation given by neutralization reaction

`n_1M_1V_1=n_2M_2V_2`

where,

`n_1,M_1\text{ and }V_1` are the n-factor, molarity and volume of acid which is
`H_3PO_4`

`n_2,M_2\text{ and }V_2` are the n-factor, molarity and volume of base which is
`Ca(OH)_2`

We are given:

`n_1=3\\M_1=0.75M\\V_1=15mL\\n_2=2\\M_2=?M\\V_2=20mL`

Putting values in above equation, we get:

`3* 0.750* 15=2* M_2* 20\\\\M_2=0.843M`

Hence, the concentration of
`Ca(OH)_2` comes out to be 0.843 M.