Question

Calculate the mass of potassium acid phthalate (HKC8H4O4) that will require about 15 mL of the approximately 0.1 M NaOH solution. Measure approximately this mass on a tared piece of weighing paper and transfer it to a clean, labeled Erlenmeyer flask. Similarly, prepare all three samples, recording the masses for each. Dissolve the KHP in about 50 mL of R.O. water and add 2 drops of phenolphthalein.

Answer 1

Answer:

0.31 g

Explanation:

The equation of the reaction;

HKC8H4O4(aq) + NaOH(aq) ----> Na(KC8H4O4)(aq) + H2O(l)

Number of moles of NaOH = 15/1000 L × 0.1 M

= 0.0015 moles

Since the reaction is 1:1, 0.0015 moles of KHP reacted;

Number of moles of KHP = mass of KHP reacted/molar mass of KHP

Mass of KHP = Number of moles of KHP × molar mass of KHP

Mass of KHP = 0.0015 moles × 204.22 g/mol

Mass of KHP = 0.31 g