Test 4 (Ch 6.1 - 6.5)

Question 1

What is a buffer composed of?

Answer 1

Significant amounts of weak acid and its conj. base or

significant amounts of strong acid and its weak base.

Question 2

What is the common ion effect?

Answer 2

An effect that exists when a solution is made of a two substances that contain common ion. Due to Le Chatliers principle, the ion the products side of the equation prevents the reaction from going as forward as far as it would otherwise.

Question 3

When calculating pH for buffer what is the general form of the equation that you use to set up ice table?

Answer 3

(HA) + (H2O) (H3O+) + (A-)

Question 4

How do you calculate percent ionization?

Answer 4

Moles H3O + / original moles acid

Question 5

What is the generic formula for Henderson HasselBach

Answer 5

pH = pKa + log( [base] / [acid])

Question 6

How do you find Ka if given Kb

Answer 6

Ka * Kb = Kw (1.0 * 10 ^-14)

Ka = (1.0 * 10 ^-14) / Kb

Question 7

What is the effective range of concentrations of acid and conj. base or vice versa for a buffer.

Answer 7

(1 to 10) or (10 to 1)

Question 8

In regard to the ratio of acid and base, when is a buffer most effective?

Answer 8

When the amounts of acid and base are equal, and when the overall concentration is high.

Question 9

What is the pH for a strong acid and strong base titration at the Equivalence point?

Answer 9

7

Question 10

Note: Cards stop at section 16.4 will update more later.

Answer 10

note