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A 0.411g sample of potassium hydrogen phthalate, KHC 8 H 4 O 4 (molar mass=204.4

ID: 792770 • Letter: A

Question

A 0.411g sample of potassium hydrogen phthalate, KHC8H4O4 (molar mass=204.44g/mol) is dissolved with 50ml of deionized water in a 125ml Erlenmeyer flask. The sample is titrated to the endpoint with 15.17ml of a sodium hydroxide solution. What is the molar concentration of the NaOH solution? Express the molar concentration of NaOH to the correct number of significant figures.(Show your calculation) A 0.411g sample of potassium hydrogen phthalate, KHC8H4O4 (molar mass=204.44g/mol) is dissolved with 50ml of deionized water in a 125ml Erlenmeyer flask. The sample is titrated to the endpoint with 15.17ml of a sodium hydroxide solution. What is the molar concentration of the NaOH solution? Express the molar concentration of NaOH to the correct number of significant figures.(Show your calculation) A 0.411g sample of potassium hydrogen phthalate, KHC8H4O4 (molar mass=204.44g/mol) is dissolved with 50ml of deionized water in a 125ml Erlenmeyer flask. The sample is titrated to the endpoint with 15.17ml of a sodium hydroxide solution. What is the molar concentration of the NaOH solution? Express the molar concentration of NaOH to the correct number of significant figures.(Show your calculation)

Explanation / Answer


NaOH + KHC8H4O4 => NaKC8H4O4 + H2O

Moles of NaOH = moles of KHC8H4O4 = mass/molar mass of KHC8H4O4

= 0.411/204.44 = 0.002010 mol


Concentration of NaOH = moles/volume of NaOH

= 0.002010/0.01517

= 0.1325 M

= 0.133 M (3 significant figures)