This preview shows pages 1–2. Sign up to view the full content.
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Unformatted text preview: Version 260 Quiz 3 Laude (52390) 1 This printout should have 8 questions. Multiplechoice questions may continue on the next column or page find all choices before answering. pH = log [H + ] pOH = log [OH ] K w = 10 14 [H + ][OH ] = K w K a K b = K w [H + ] = K a ( C a /C b ) pH = p K a + log( C b /C a ) [OH ] = K b ( C b /C a ) pOH = p K b + log( C a /C b ) [H + ] = ( K ax K ay ) 1 / 2 pH = 0 . 5(p K ax + p K ay ) 001 5.0 points What would be the pH of a 1 M solution of Na 2 HPO 4 ? Assume H 3 PO 4 has a p K a 1 of 2 and a p K a 2 of 7 and a p K a 3 of 13. 1. 4.5 2. 2 3. 13 4. 10 correct 5. 7 6. 7.5 Explanation: For a solution composed of a single ampho teric species (HPO 4 2 ), pH = 0 . 5(p K a 2 + p K a 3 ) = 0 . 5(7 + 13) = 10 002 5.0 points One liter of a buffer containing 2 M H 2 CO 3 and 1 . 5 M NaHCO 3 has 24 g of LiOH added to it. What is the new pH? Assume the K a 1 of H 2 CO 3 is 2 . 5 10 4 . 1. 6 2. 3 3. 11 4. 4 correct 5. 10 6. 8 Explanation: (24 g LiOH) parenleftbigg 1 mol 24 g parenrightbigg = 1 mol LiOH [H + ] = K a ( C a /C b ) = ( 2 . 5 10 4 ) (1 M...
View Full
Document
 Spring '09
 Laude

Click to edit the document details