Question

A sample of solid calcium hdroxide, Ca(OH)2 is allowed to stand in water until a saturated solution is formed. A titration of 75.00mL of this solution with 5.00 x 10-2 M HCl 36.6 mL of the acid to reach the end point

Ca(OH)2 + 2HCl ? CaCl + 2H2O
What is the molarity?

Answer 1

Answer: The concentration of
`Ca(OH)_2` is 0.0122 M.

Step-by-step explanation:

To calculate the concentration of base, 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
`HCl`

`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=1\\M_1=5.00* 10^(-2)M=0.05M\\V_1=36.6mL\\n_2=2\\M_2=?M\\V_2=75mL`

Putting values in above equation, we get:

`1* 0.05* 36.6=2* M_2* 75\\\\M_2=0.0122M`

Hence, the concentration of
`Ca(OH)_2` is 0.0122 M.