Question

The flask contains 10.0 mL 10.0 mL of HCl HCl and a few drops of phenolphthalein indicator. The buret contains 0.130 M NaOH . 0.130 M NaOH. It requires 32.4 mL 32.4 mL of the NaOH NaOH solution to reach the end point of the titration.

Answer 1

The question is incomplete, here is the complete question:

The flask contains 10.0 mL of HCl and a few drops of phenolphthalein indicator. The buret contains 0.130 M NaOH. It requires 32.4 mL of the NaOH solution to reach the end point of the titration.  What is the concentration of HCl ?

Answer: The concentration of HCl is 0.421 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 HCl

$n_2,M_2\text{ and }V_2$ are the n-factor, molarity and volume of base which is NaOH.

We are given:

$n_1=1\\M_1=?M\\V_1=10.0mL\\n_2=1\\M_2=0.130M\\V_2=32.4mL$

Putting values in above equation, we get:

$1\times M_1\times 10.0=1\times 0.130\times 32.4\\\\M_1=\frac{1\times 0.130\times 32.4}{1\times 10.0}=0.421M$

Hence, the concentration of HCl is 0.421 M