Question

Using your calculated concentration of NaOH from lab how many grams of KHP would you need to start with in order to have an end point at 35.00 mL?

Do I use 71.08 or 204.22 for KHP Molecular Mass? Concentration of NaOH from the Experiment was .356.

Answer 1

we are doing a nuetralization reaction

KHC8H4O4 + NaOH = NaKC8H4O4 + H2O

KHP + sodium hydroxide

Given

Molarity of NaOH = 0.356 M ( or mol/L)

Volume for end point = 35 ml = 0.035 L

No. of moles of NaOH to be used = Volume of NaOH for end point * Molarity of NaOH used = 0.035 L * 0.356 M

= 0.01246 moles

so we require equal no of moles to nuetralize this many moles of NaOH

so No. of moles of KHP that has to be taken = 0.01246 moles

Molar mass of KHP = 204.22 g/mol

Mass of KHP that has to be taken = No. of moles * Molar mass = 0.01246 * 204.22 = 2.54 g

so we need 2.54 g of KHP to reach an endpoint of 35 ml