Calculate the approximate volume of the NaOH solution that will be needed to neutralize approximately 0.800 g of KHC8H4O4.

Question

1. Calculate the approximate volume of the NaOH solution that will be needed to neutralize approximately 0.800 g of KHC8H4O4.

I have no idea how to solve this question. please teach me how to do this problem

Answer 1

You can't answer this without knowing the concentration of the NaOH solution being used. Assuming you have this information but forgot to include it, you proceed as follows:

KHC₈H₄O₄ is potassium hydrogen phthalate (KHP). It is an acidic salt of phthalic acid, and still has ONE acid hydrogen remaining which can be titrated. Let us write the balanced equation for the reaction:

KHC₈H₄O₄ + NaOH ==> KNaC₈H₄O₄ + HOH (I've made the acidic H bold)

So, the stoichiometry is 1 moles NaOH needed for 1 mole of KHP.

How many moles of KHP are present? Molar mass of KHP = 204 g/mol

0.800 g KHP x 1 mole KHP/204 g = 0.00392 moles

It will take 0.00392 moles of NaOH to neutralize this. Knowing the molarity of the NaOH, you can then solve for the volume of NaOH needed.