5.1.3: Acids, bases and buffers Flashcards
Define a Bronsted-Lowry acid
Proton donor
Define a Bronsted-Lowry base
Proton acceptor
Define Lewis acid
Electron pair acceptor
Define Lewis base
Electron pair donor
What ion causes a solution to become acidic? (2 answers) Name and formula
H+ (hydrogen ion) or, more accurately, H3O+ (oxonium ion), as protons react with H2O to form it
What ion causes a solution to become alkaline?
-OH (hydroxide ion)
Write an equation for the ionisation of water (2 marks)
2H2O (l) ⇌ H3O+ (aq) + -OH (aq) OR H2O (l) ⇌ H+ (aq) + -OH (aq)
Give example of a monobasic acid
HCl
Give example of a dibasic acid
H2SO4
Give example of a tribasic acid
H3PO4
Identify the acid base pairs for the reaction below
CH3COOH + H2O ⇌ CH3COO- + H3O+
Acid 1: CH3COOH
Base 2: H2O
Base 1: CH3COO-
Acid 2: H3O+
Define strong acid
Acids dissociate completely
Give some examples of strong acids
● Hydrochloric acid
● Sulfuric acid
● Nitric acid
What is the difference between concentrated and strong?
Concentrated means many mol per dm3,
strong refers to amount of dissociation
Define weak acids
Acids that only partially dissociate
Give some examples of weak acid
Methanoic acid, any organic acid
What is constant that is used to measure the extent of acid dissociation called?
Acid dissociation constant
What is the symbol of acid dissociation constant?
Ka
What does a larger Ka value mean?
Larger the Ka - greater the extent of
dissociation
Write the equation used to convert Ka into pKa
pKa = -log10Ka
Write the equation used to convert pKa
into Ka
Ka= 10-pKa
What is the relationship between pKa and strength of the acid?
Smaller the pKa stronger the acid