{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

LQs for web 3-7 to 3-9-06

# LQs for web 3-7 to 3-9-06 - Tuesday In-Lecture To Do List 1...

This preview shows pages 1–6. Sign up to view the full content.

Tuesday 3-7-06 In-Lecture To Do List 1. Website – exam time and places 1. Bring Calculators (only approved types!) 2. Bring Buck ID – Cannot take exam without it 2. Finish Chapter 17 (up to 17.3 only) 3. Qs & LQ: Henderson Hasselbalch clarification & titration problems

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

View Full Document
Q1. What is the pH of a solution made by combining 600.0 mL of 1.667 M acetic acid and 400.0 mL of 0.0250 M sodium acetate? (K a =1.80x10 -5 ) 2.745 2.808 2.735 1.8 x 10-5 I’m guessing 31% 20% 40% 2% 7% 1. 2.745 2. 2.808 3. 2.735 4. 1.8 x 10 -5 5. I’m guessing
Q2. What is the pH of a solution made by combining 600.0 mL of 1.667 M acetic acid and 400.0 mL of 0.250 M sodium acetate? (K a =1.80x10 -5 ) 3.745 7.345 3.746 1.8 x 10-5 I’m guessing 24% 7% 18% 2% 48% 1. 3.745 2. 7.345 3. 3.746 4. 1.8 x 10 -5 5. I’m guessing

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

View Full Document
Q1. use ICE table, particularly when ratio is less than 0.1. ICE table will be correct! _____________ PH 2.8082 = pH 2.7447 = H 1.5553 10 3 × = PH log H ( ) := pH pKa log x ( ) + := H b b 2 4 a c ( ) 0.5 + 2 a := pKa 4.7447 = b 0.01 = c 1.8 10 5 × = b base Ka + := pKa log Ka ( ) := c Ka := a 1 := acid 1 := Ka 1.8 10 5 := base x := x 0.01 := HH INCORRECT IN THE 10 TH PLACE AND BEYON ICE TABLE: GIVES ACCURATE (CORRECT) pH of 2.808 Note: H - is negative
Q2. ratio is 0.1, otherwise same problem as Q1, but using HH eqn will work if you only need 2 sig figs after the decimal place of the pH. PH 3.7456 = pH 3.7447 = H 1.7964 10 4 × = PH log H ( ) := pH pKa log x ( ) + := H b b 2 4 a c ( ) 0.5 + 2 a := pKa 4.7447 = b 0.1 = c 1.8 10 5 × = b base Ka + := pKa log Ka ( ) := c Ka := a 1 := acid 1 := Ka 1.8 10 5 := base x := x 0.1 :=

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

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

### What students are saying

• As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

Kiran Temple University Fox School of Business ‘17, Course Hero Intern

• I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

Dana University of Pennsylvania ‘17, Course Hero Intern

• The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

Jill Tulane University ‘16, Course Hero Intern