<u>Answer:</u> The mass of acetic acid used is 0.12 grams
<u>Explanation:</u>
To calculate the concentration of acid, we use the equation given by neutralization reaction:

where,
are the n-factor, molarity and volume of acid which is 
are the n-factor, molarity and volume of base which is NaOH.
We are given:

Putting values in above equation, we get:

To calculate the mass of solute, we use the equation used to calculate the molarity of solution:

Given mass of acetic acid = ? g
Molar mass of acetic acid = 60.05 g/mol
Molarity of solution = 1 M
Volume of the solution = 2.0 mL
Putting values in above equation, we get:

Hence, the mass of acetic acid used is 0.12 grams