Acid/base Equilibria Flashcards Preview

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Flashcards in Acid/base Equilibria Deck (14)
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0

What is the equation for the ionic product of water?

Kw= [H+][OH-]

1

What 2 assumptions are made when finding the pH of a weak acid?

1. The initial conc. = conc. at equilibrium

2. [RCOO-] = [H+] Therefore numerator simplifies to [H+]2

2

What pH does the vertical portion for a strong acid/strong base titration curve cover?

pH 3-11

3

What is the equivalence point of a strong acid/strong base titration curve?

pH= 7

4

What is the pH range of the vertical section of a strong acid/weak base titration curve?

pH 3-7

5

Where is the buffered region of a strong acid/weak base titration curve?

pH 9-11

6

Give two equations to show the buffer effect of a weak base.

1. NH4+ + OH- = NH3 + H2O

2. NH3 + H+ = NH4+

7

What is the pH range of the vertical section of a weak acid/strong base titration curve?

pH 7-11

8

Where is the buffered region of a weak acid/strong base titration curve?

pH 5

9

Give two equations to show the buffer effect of a weak acid

1. CH3COOH- + H+ = CH3COOH

2. CH3COOH + OH- = CH3COO- + H2O

10

Where must the pH range of an indicator lie in order for it to be suitable for a certain acid/base titration?

Well within the vertical section of the acid/base titration curve

11

Give the definition of a buffer solution.

A buffer solution is one that minimises small changes in pH. A buffer solution consists of a weak acid and one of its salts (conjugate base).

12

Name three indicators.

1. Bromothymol Blue
2. Phenolphthalein
3. Methyl Orange

13

What is [H+] in terms of pH?

[H+]= 10*-pH