2010F - CHEM 126101 Chapter 16 Regular Homework Acids II

2010F - CHEM 126101 Chapter 16 Regular Homework Acids II -...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
10F - CHEM 126101 - GEN CHEMISTRY II You are logged in as Andrew Sindt ( Logout ) You are here NJIT / ► 2010F - CHEM 126101 / ► Quizzes / ► Chapter 16 Regular Homework: Acids II / ► Review of attempt 2 Chapter 16 Regular Homework: Acids II Review of attempt 2 Started on Saturday, 23 October 2010, 10:39 PM Completed on Saturday, 23 October 2010, 11:45 PM Time taken 1 hour 5 mins Finish review
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Marks 22.17/29 Grade 7.64 out of a maximum of 10 ( 76 %) Question 1 Marks: 1 Titration of a weak acid Calculate the pH during the titration of 10.00 mL of 0.400 M hypochlorous acid with 0.500 M NaOH. First what is the initial pH (before any NaOH is added)? The K a for HOCl is 3.0 x 10 -8 M. Need help? Hint, given in general feedback. Answer: Make ICE table and use simplified method of successive approximations (no iterations needed). Correct Marks for this submission: 1/1. Question 2 Marks: 1 How many mL of NaOH are added to reach the equivalence point? Answer: Correct Marks for this submission: 1/1. Question 3 Marks: 1 What is the pH after 3.20 mL of NaOH are added? Hint given in general feedback. Answer: Hint, note that the amount NaOH added is less than what is needed to completely neutralize acid. So, you have made a buffer. Use buffer equation. Incorrect Marks for this submission: 0/1. Question 4 Marks: 1 What is the pH after 7.30 mL of NaOH are added? Hint given in general feedback. Answer: Hint, note that the amount NaOH added is less than what is needed to completely neutralize acid. So, you have made a buffer. Use buffer equation. Incorrect Marks for this submission: 0/1. Question 5 Marks: 1 What is the pH at the equivalence point? Notice that the pH of a weak acid at the equivalence point is basic.
Background image of page 2
Correct Marks for this submission: 1/1. Question 6 Marks: 1 What is the pH after 10.90 mL of NaOH are added? Hint given in general feedback. Answer: Hint, note that the amount NaOH added is more than what is needed to completely neutralize acid. So, you have strong base plus a weak base. Incorrect Marks for this submission: 0/1. Question 7 Marks: 1 What is the pH when half the acid has been neutralized? Hint given in general feedback. Answer: This is the easiest problem. Think buffer eq. . . Correct Marks for this submission: 1/1. Question 8 Marks: 1 What is the pH after 16.10 mL of NaOH are added? Hint given in general feedback. Answer: Hint, note that the amount NaOH added is more than what is needed to completely neutralize acid. So, you have strong base plus a weak base. Incorrect Marks for this submission: 0/1. Question 9 Marks: 1 Chloropropionic acid, ClCH 2 CH 2 COOH is a weak monoprotic acid with K a = 7.94 x 10 -5 M. Calculate the pH at the equivalence point in a titration 38.6 mL of 1.72 M chloropropionic acid with 0.2 M KOH. Answer:
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/09/2010 for the course CHEM Chem taught by Professor Petrova during the Spring '09 term at NJIT.

Page1 / 12

2010F - CHEM 126101 Chapter 16 Regular Homework Acids II -...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online