Question

An aqueous solution of calcium hydroxide is standardized by titration with a 0.120 M solution of hydrobromic acid. If 16.5 mL of base are required to neutralize 27.5 mL of the acid, what is the molarity of the calcium hydroxide solution?

Answer 1

Answer: The molarity of calcium hydroxide in the solution is 0.1 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
`HBr`

`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=0.120M\\V_1=27.5mL\\n_2=2\\M_2=?M\\V_2=16.5mL`

Putting values in above equation, we get:

`1* 0.120* 27.5=2* M_2* 16.5\\\\M_2=0.1M`

Hence, the molarity of
`Ca(OH)_2` in the solution is 0.1 M.