Question

A 30.00 mL sample of HBr was titrated using 0.1756 M NaOH. Determine the concentration of the HBr sample if 17.52 mL of NaOH was required to reach the endpoint in the titration.

Answer 1

Answer: The concentration of HBr sample is 0.1025 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 HBr

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

We are given:

$n_1=1\\M_1=?M\\V_1=30.00mL\\n_2=1\\M_2=0.1756M\\V_2=17.52mL$

Putting values in above equation, we get:

$1\times M_1\times 30.00=1\times 0.1756\times 17.52\\\\M_1=\frac{1\times 0.1756\times 17.52}{1\times 30.00}=0.1025M$

Hence, the concentration of HBr sample is 0.1025 M