Lecture 8

Question 1

What does a high vs low Ka say about the acid

Answer 1

High = strong acid
–> will go to the right to create p+
–> weak conjugate base
–> eq is to the right (doesn’t come back, breaks up and stays to the right, goes one way)
Low = Weak acid
–> won’t go as far to the right - stays mostly to the left
–> strong conjugate base

Question 2

Ka expression?

Answer 2

Ka = [H+][A-]/[HA]

Question 3

What is Kw

Answer 3

Acid dissociation constant of water
Kw = [H+][OH-]

REMEMBER:
at 25 degrees, [H+] = [OH-] = 1.0x10^-7
SOO Kw = 1.0x10^-14

Question 4

How are [H+] and [OH-] related in neutral, acidic and basic solutions

Answer 4

Neutral: [H+] = [OH-]
Acidic: [H+] > [OH-]
Basic: [H+] < [OH-]

Question 5

What is the pH scale and equation

Answer 5

Used to describe solution acidity
pH = -log[H+]
14 = pH + pOH

REMEMBER: sig figs must also be AFTER decimal place