If the titration of 0.8094 g of 100% pure KHP requires 40.25 mL of NaOH, what
is the concentration of the NaOH
solution? Remember KHP is potassium
hydrogen phthalate, KHC2H4O4. Show
this calculation in your lab notebook.

Explanation:

molecular weight of potassium hydrogen phthalate = 204

.8094 g of KHP = .8094 / 204 = 3.967 x 10⁻³ moles

3.967 x 10⁻³ moles of KHP must have reacted with 3.967 x 10⁻³ moles of NaOH

concentration of NaOH = 3.967 x 10⁻³ / 40.25 x 10⁻³

= .098 M .

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.