Question

please write out calculations for each box missing an answer

data the experiment Record For the lab report, attach this data sheet (signed by your TA) to your calculations page. REPORT ALL VALUES TO AT LEAST THREE SIGNIFICANT FIGURES. READ YOUR BURETTE TO THE NEAREST 0.05 mL increment. for on this sheet. Do your calculations on a separate piece of paper. Part One-Standardization of a NaOH solution of approximately 0.1 M. Trial 1 | Trial 2 | Trial 3 Mass of KHP (g) Moles of KHP Initial burette 002550 reading for NaOH Final burette reading for NaOH .S7 Volume of NaOH used (mL) Molarity of NaOH Average molarity ± standard deviation Part Two - Determination of the concentration of an unknown HCI solution of appr imately 0.1 M. ox- TrialTrial 2 27 So 22.80 S Volume of HCI sample Initial burette reading for NaOH (mL) Final burette reading for NaOH (mL) Volume of NaOH used (mL) Moles of NaOH used Average molarity Molarity of HCl sample Standardization of a NaOH Solution and Titration of an Unknown HCI Solution Note: Be sure to read the burette to the nearest 0.05 mL. increment. When titrating, do not allow the NaOH solution to go below the lowest marking on the burette. Examples of correct readings: Examples ofincorrect readings: "O. 15 ml.", "10.00 mL". "I 365 mL", "4020 mL", etc. "O.16mL”, “10.02m1","13.64 mL", "40.21 mL", etc. Part One- Standardization of NaOH solution: 1. Gather 3 clean Erlenmeyer flasks 2. Use weighing paper to weigh out 0.4000 g of KHP; the goal is to get close to 0.4000 g, but it doesn't have to be exactly 0.4000 g 3. Record the exact mass of the KHP on the data sheet 4 Quantitatively transfer the KHP into your first Erlenmeyer flask 5. Repeat this same procedure for the other two Erlenmeyer flasks 6. Add 100 mL of DI water to each of the three flasks and swirl to completely dissolve the KHP 7. Add 3 drops of phenolphthalein indicator to each flask and swirl to mix well You now have three 100 mL KHP solutions ready to titrate 8. Rinse your burette with DI water and two small rinses of NaOH solution 9. Fill your burette with NaOH solution 10. You are free to adjust the NaOH level in the burette before beginning your first titration but be sure to record the initial volume. For example, you may start on 0.00 mL, 0.50 mL., 1.00 mL, 5.00 mL, etc.; the important point is that you record the exact initial volume 11. Titrate the first KHP solution to the endpoint. Swirl the flask frequently while titrating. At the endpoint, you want a FAINT PINK solution with color that persists for -30 seconds 12. Record the final volume of NaOH solution 13. Repeat the titration for the other two KHP solutions, being sure to record initial and final 14. Dispose of titrated solutions down the sink volumes of NaOH on your data sheet Part Two- Titration of unknown HCI solution using the standardized NaOH solution: 1. Using a clean 100 mL graduated cylinder, add a volume of unknown HCl specified by your TA to a clean Erlenmeyer flask 2. Record this volume on your data sheet 3. Repeat this step for a second flask 4. Add 3 drops of phenolphthalein indicator to each of these two flasks and swirl to mix well 5. Titrate each of these two solutions to the endpoint using your standardized NaOH. Swirl the flask frequently while titrating. At the endpoint, you want a FAINT PINK solution with color that persists for 30 seconds 6. Be sure to record the initial and final volumes of NaOH 7. Dispose of titrated solutions down the sink. Neutralize any excess NaOH with acid, and 8. Rinse the burette with both tap water and several rinses of DI water before returning it to any excess HCI with base provided by your TA and wash down the sink the stockroom Note: Please be conservative with the KHP and the NaOH and HCI solutions; try not to remove more chemicals from the stock containers than you plan on using.

Answer 1

Molar mass of KHP ( potassium hydrogen pthalate) = 204.22 g/mol

TRAIL 1

mass of KHP taken = 0.4106 g

moles of KHP = mass /molar mass

= 0.4106 g / 204.22 g/mol

= 0.00020

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

1 equivalent of NaOH =   1 equivalent of  KHC₈H₄O₄

moles of NaOH required to neutralize KHP = 0.00020

volume of NaOH = 19 55 ml

molarity of NaOH = moles x 1000/ volume in ml

=  0.00020 x 1000 / 19 55 ml

= 0.1028 M

HCl - NaOH titration

HCl + NaOH ----------------> NaCl + H₂O

1 equivalent of HCl = 1 equivalent of NaOH

volume of NaOH = 21.80 ml

moles of NaOH = Molarity x volume in ml / 1000

= 0.1028M x 21.80 ml / 1000

= 0.00224 moles

1 equivalent of HCl = 1 equivalent of NaOH

volume of HCl = 25 ml

Molarity of HCl = moles x 1000 /25 ml

= 0.00224 moles x 1000/25

= 0.0896M

OR

Molarity of HCl = molarity of NaOH x volume of NaOH / volume of HCL

= 0.1028 M x 21.80 ml/ 25 ml

= 0.0896 M

TRAIL 2

mass of KHP taken = 0.4026 g

moles of KHP = mass /molar mass

= 0.4026 g / 204.22 g/mol

= 0.00197

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

1 equivalent of NaOH =   1 equivalent of  KHC₈H₄O₄

moles of NaOH required to neutralize KHP = 0.00197

volume of NaOH = 19 20 ml

molarity of NaOH = moles x 1000/ volume in ml

=  0.00197 x 1000 / 19 20 ml

= 0.1027 M

HCl - NaOH titration

HCl + NaOH ----------------> NaCl + H₂O

1 equivalent of HCl = 1 equivalent of NaOH

volume of NaOH = 22.15 ml

moles of NaOH = Molarity x volume in ml / 1000

= 0.1027M x 22.15 ml / 1000

= 0.00227 moles

1 equivalent of HCl = 1 equivalent of NaOH

volume of HCl = 25 ml

Molarity of HCl = moles x 1000 /25 ml

= 0.00227 moles x 1000/25 ml

= 0.0909 M

TRAIL 3

mass of KHP taken = 0.4065 g

moles of KHP = mass /molar mass

= 0.4065 g / 204.22 g/mol

= 0.00199

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

1 equivalent of NaOH =   1 equivalent of  KHC₈H₄O₄

moles of NaOH required to neutralize KHP = 0.00199

volume of NaOH = 19 50 ml

molarity of NaOH = moles x 1000/ volume in ml

=  0.00199 x 1000 / 19 50 ml

= 0.1021 M

Average molarity of NaOH = (0.1028 M + 0.1027 M + 0.1021 M )/3

= 0.1025 M

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standard deviation =

rn O lo28-o los) 10 2 o lo25)6lo11-o.lo25) 2 7