topic 8.4 and 18.2 - strengths of acids/bases and calculations

Question 1

pKa

Answer 1

-log(Ka)

Question 2

pKb

Answer 2

-log(kb)

Question 3

pH

Answer 3

-log(H⁺(aq))

14 - pOH

Question 4

pOH

Answer 4

-log(OH⁻(aq))

14 - pH

Question 5

Ka

Answer 5

10⁻ᵖᴷᵃ

(H⁺(aq))²/HA

Question 6

Kb

Answer 6

10⁻ᵖᴷᵇ

(OH⁻(aq))²/b

Question 7

H⁺

Answer 7

√(Ka x HA)
10⁻ᵖᴴ
Kw/(OH⁻)

Question 8

OH⁻

Answer 8

√(Kb x b)
10⁻ᵖᴼᴴ
Kw/(H⁺)

Question 9

Strong acid

Weak acid

Answer 9

Effective proton donor - completely ionises in water (->)

Poor proton donor - partially dissociates in water (⇌)

Question 10

Strong base

Weak base

Answer 10

Effective proton acceptor - completely ionises (->)

Poor proton acceptor - partially dissociates in water (⇌)

Question 11

Finding the strength of acid/base using conductivity

Answer 11

More ionisation leads to more ions in the solution so more electricity can be transmitted through a solution.
Stronger acid/base causes a light bulb to shine brighter.

Question 12

Finding the strength of acid/base using neutralisation

Answer 12

Complete ionisation leads to more exothermic reactions occurring. Stronger acid - more exothermic reaction.

Incomplete ionisation leads to less exothermic reactions taking place. Weaker acid - less exothermic.

Stronger acid causes a more exothermic reaction than a weaker acid.

-57 KJ/mol - standard for neutralisation with a strong acid.

Question 13

Finding the strength of acid/base using rate of reaction

Answer 13

Stronger acids and bases will have a faster rate of reaction.