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: The concentration of \(Ca(OH)_2\) comes out to be 0.843 M.
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:
\(n_1=3\\M_1=0.75M\\V_1=15mL\ _2=2\\M_2=?M\\V_2=20mL\)
Putting values in above equation, we get:
\(3\times 0.750\times 15=2\times M_2\times 20\\\\M_2=0.843M\)
Hence, the concentration of \(Ca(OH)_2\) comes out to be 0.843 M.