<u>Answer:</u> The mass of HCl present in 500 mL of acid solution is 36.5 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 HCl
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:

Molar mass of HCl = 36.5 g/mol
Molarity of solution = 2 M
Volume of solution = 500 mL
Putting values in above equation, we get:

Hence, the mass of HCl present in 500 mL of acid solution is 36.5 grams