Question

A 60.00-mL sample of a weak acid is titrated with 0.0361 M NaOH. At the endpoint, it is found that 38.23 mL of titrant was used. What was the concentration of the weak acid?

Answer 1

Answer: The concentration of weak acid is 0.0230 M

Step-by-step 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 weak acid

`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=2\\M_1=?M\\V_1=60.00mL\\n_2=1\\M_2=0.0361M\\V_2=38.23mL`

Putting values in above equation, we get:

`1* M_1* 60.00=1* 0.0361* 38.23\\\\M_1=(1* 0.0361* 38.23)/(1* 60.00)=0.0230M`

Hence, the concentration of weak acid is 0.0230 M