Answer: The molarity of the malonic acid solution is 0.08335 M
Step-by-step explanation:

To calculate the molarity 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:

Thus the molarity of the malonic acid solution is 0.08335 M