Need help on the whole page n a known volume of solution, multi- known vol a of

Question

Need help on the whole page

n a known volume of solution, multi- known vol a of solute present aumber of males iewBy the molarity (liters(moles) NAME REPORT FOR EXPERIMENT 22 (continued) QUESTIONS AND PROBLEMS 1. If you had added 50 mL of water to a sample of KIHIP instead of 30 mL, would the titra- tion of that sample then have required more, less, or the same amount of base? Exp tion te 2. A student weighed out 1.106 g of KHP How many moles was that? 3. A titration required 18.38 mL of 0.1574 M NaOH solution. How many moles of NaOH were in this volume? mol 4. A student weighed a sample of KHP and found it weighed 1.276 g. Titration of this KHP required 19.84 mL of base (NaOH). Calculate the molarity of the base. 5. Forgetful Freddy weighed his KHP sample, but forgot to bring his report sheet along, so he recorded the mass of KHIP on a paper towel. During his titration, which required Figure 22. heavy dar vision of niscus m ad. The 18.46 mL of base, he spilled some base on his hands. He remembered to wash but forgot about the data on the towel, and used it to dry his hands. When he went to calculate the molarity of his base, Freddy discovered that he didn't have the mass of his KHP His kindhearted instructor told Freddy that his base was 0.2987 M. Calculate the mass of Freddy's KHP sample. 6. What mass of solid NaOH would be needed to make 645 mL of Freddy's NaOH solution? 200 - -

Explanation / Answer

Answer:

2) Molar mass of KHP = 204.22 g mol-1

moles of KHP = mass of KHP / molar mass of KHP = 1.106 g / 204.22 g/mol = 0.0054 mol

Step1 Molar mass of Potassium Hydrogen Pthalate = 204.22

HOOCC6H4COOK

Step2 Given mass = 1.106

Step3 Moles = 1.106/204.22 =.005416 ; [ 4 significant digits]

4) 1.276/204 = .0063 moles of KHP, which must require .0063 moles of NaOH.

NaOH and KHP reacts as:

NaOH(aq) + KHC8H4O4(aq)= KNaC8H4O4(aq) +H2O(l)

from above reaction, at equivalence point,

mol of NaOH = mol of KHP

M(NaOH) * V (NaOH) = mol of KHP

Thus the molarity of NaOH = .0063/(19.84/1000) = 0.318 M.

Related Questions

Navigate

• Browse (All)
• Browse N
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.