Exam2_1_S2004 - How many mL of 0.01 M HCl must be added to...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
Exam #2 Chemistry 112 Spring 2004 Name: __________________________________ Social Security Number: ___________________ For ALL pH questions, express the answer to 2 decimal places !!! Write neatly !!! Show all work !!! [H 3 O + ][OH - ] = 1 x 10 -14 = k w pH + pOH = 14 = pk w pH = - log[H 3 O + ] [H 3 O + ] = 10 - pH pOH = - log[OH - ] [OH - ] = 10 - pOH [HA] ] ][A O [H k 3 a + = ] [A ] [HA][OH [BOH] ] ][OH [B k b + = or k a k b = k w pk a + pk b = pk w pH = pk a + log n b n a = a b a C C log pk + ay 2 + by + c = 0 y = b ± b 2 4ac 2a 1
Background image of page 1

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

View Full DocumentRight Arrow Icon
1. (10 points) List the following solutions in the order from most acidic to most basic: 0.5 M KCl 0.1 M HI 0.18 M CH 3 COONa 0.45 M Ca(OH) 2 0.217 M NH 4 Br 2
Background image of page 2
2. (10 points) Calculate the pH of a mixture of 20 mL of 0.4 M KOH and 30 mL of 0.15 M CH 3 COOH. K a (CH 3 COOH) = 1.8×10 -5 . 3
Background image of page 3

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

View Full DocumentRight Arrow Icon
3. (10 points) How many grams of dry NaOH must be added to 200 mL of 0.4 M H 2 SO 4 to neutralize it completely? Molar mass of NaOH is 40 g/mol. 4
Background image of page 4
4. (10 points) CN- is a weak base with K b =1.39×10 -5 (it is also a very strong poison). Your job is to prepare a neutral solution with this ion.
Background image of page 5

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

View Full DocumentRight Arrow Icon
Background image of page 6
Background image of page 7

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

View Full DocumentRight Arrow Icon
Background image of page 8
Background image of page 9

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

View Full DocumentRight Arrow Icon
Background image of page 10
Background image of page 11
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: How many mL of 0.01 M HCl must be added to 10 mL of 0.02M of KCN to make a pH = 7 solution? 5 5. (10 points) Calculate the pOH of 0.02 M solution of HOCl, its K a =3.0×10-8 . 6 6. (50 points) Titration: This is a multi-step problem. Calculate the pH for the titration of 20 mL of 0.20 M HCOOH, K a = 1.8 x 10-4 , with 0.1 M LiOH. a) (11 points) Before any base is added. b) (13 points) After 20 mL of base is added. c) (13 points) After 40 mL of base is added d) (13 points) After 60 mL of base is added a) 0 mL of LiOH have been added 7 b) 20 mL of LiOH have been added 8 c) 40 mL of LiOH have been added 9 d) 60 mL of LiOH have been added 10 9. (15 challenge bonus points). Calculate the pH of a mixture of 100 mL of 0.2 M H 3 PO 4 with 50 mL of 1.0 M NaOH. For phosphoric acid K a1 = 7.5 x 10-3 , K a2 = 6.2 x 10-8 , K a3 = 2.2 x 10-13 . 11...
View Full Document

This note was uploaded on 10/03/2011 for the course CHEM 112 taught by Professor Chen during the Spring '09 term at South Carolina.

Page1 / 11

Exam2_1_S2004 - How many mL of 0.01 M HCl must be added to...

This preview shows document pages 1 - 11. Sign up to view the full document.

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