Name Experiment 4-Prelab Assignment 1. A 0.219 g sample of an unknown organic acid was titrated with 0.0934 M NaOH; a total of 39.52 mL of the base solution was required to reach the end-point. The acid is known to have 2 carboxyl groups per molecule. What was the molecular weight of the unknown acid? Show all calculations. 2. The melting point of the unknown acid in question 1, above, was found to be 179-182°C and the acid was soluble in water. Which of the following acids is most likely to be the unknown acid? Acid 1 Acid 2 Acid 3 Molecular Mass Solubility 118 g/mole 117 g/mole 120 g/mole water soluble water soluble water soluble Melting Point 147 - 149 °C 170-172 °C 185 186 °C

Name Experiment 4-Prelab Assignment 1. A 0.219 g sample of an unknown organic acid was titrated with 0.0934 M NaOH; a total of 39.52 mL of the base solution was required to reach the end-point. The acid is known to have 2 carboxyl groups per molecule. What was the molecular weight of the unknown acid? Show all calculations. 2. The melting point of the unknown acid in question 1, above, was found to be 179-182°C and the acid was soluble in water. Which of the following acids is most likely to be the unknown acid? Acid 1 Acid 2 Acid 3 Molecular Mass Solubility 118 g/mole 117 g/mole 120 g/mole water soluble water soluble water soluble Melting Point 147 - 149 °C 170-172 °C 185 186 °C

Chemistry: Principles and Reactions

8th Edition

ISBN:9781305079373

Author:William L. Masterton, Cecile N. Hurley

Publisher:William L. Masterton, Cecile N. Hurley

Chapter14: Equilibria In Acid-base Solutions

Section: Chapter Questions

Problem 74QAP: Fifty cm3 of 1.000 M nitrous acid is titrated with 0.850 M NaOH. What is the pH of the solution (a)...

See similar textbooks

Similar questions

Figure 15-3 outlines the classic scheme for separating a mixture of insoluble chloride salts from one another. Explain the chemistry involved in the various steps of the figure.
Malonic acid (HO2CCH2CO2H) is a diprotic acid. In the titration of malonic acid w ith NaOH, stoichiometric points occur at pH = 3.9 and 8.8. A 25.00-mL sample of malonic acid of unknown concentration is titrated with 0.0984 M NaOH, requiring 31.50 mL of the NaOH solution to reach the phenolphthalein end point. Calculate the concentration of the initial malonic acid solution. (Sec Exercise 113.)
Fifty cm3 of 1.000 M nitrous acid is titrated with 0.850 M NaOH. What is the pH of the solution (a) before any NaOH is added? (b) at half-neutralization? (c) at the equivalence point? (d) when 0.10 mL less than the volume of NaOH to reach the equivalence point is added? (e) when 0.10 mL more than the volume of NaOH to reach the equivalence point is added? (f) Use your data to construct a plot similar to that shown in Figure 14.10 (pH versus volume NaOH added).
Consider the following four titrations. i. 100.0 mL of 0.10 M HCl titrated by 0.10 M NaOH ii. 100.0 mL of 0.10 M NaOH titrated by 0.10 M HCl iii. 100.0 mL of 0.10 M CH3NH2 titrated by 0.10 M HCl iv. 100.0 mL of 0.10 M HF titrated by 0.10 M NaOH Rank the titrations in order of: a. increasing volume of titrant added to reach the equivalence point. b. increasing pH initially before any titrant has been added. c. increasing pH at the halfway point in equivalence. d. increasing pH at the equivalence point. How would the rankings change if C5H5N replaced CH3NH2 and if HOC6H5 replaced HF?
For the titration of 50.0 mL of 0.100-M HCl with 0.100-M NaOH, calculate the pH when these volumes of NaOH have been added: (a) 10.0 mL (b) 25.00 mL (c) 45.0 mL (d) 50.5 mL
The following plot shows the pH curves for the titrations of various acids by 0.10 M NaOH (all of the acids were 50.0-mL samples of 0.10 M concentration). a. Which pH curve corresponds to the weakest acid? b. Which pH curve corresponds to the strongest acid? Which point on the pH curve would you examine to see if this acid is a strong acid or a weak acid (assuming you did not know the initial concentration of the acid)? c. Which pH curve corresponds to an acid with Ka 1 106?
Which of the indicators in Fig. 14-8 could be used for the titrations in Exercises 61 and 63?