Fundamentals of Acids & Bases Flashcards
What is a Bronsted Acid?
A species that can donate a proton
What is a Bronsted base?
A species that can accept a proton
What are conjugate acid-base pairs?
Two species that are different from each other by an H+ ion
What is pH defined as?
pH = -log[H+]
What does the acidity of an aqueous solution depend on?
Number of H+ ions in solution
How can the concentration of H+ of a solution be calculated?
[H+] = 10⁻ᵖᴴ
How do strong acids behave in solution?
Completely ionised
What is the equation for strong acids in solution?
HA (aq) → H+ (aq) + A- (aq)
What is diprotic acid?
Acid with two replaceable protons that react in a 1:2 ratio with bases
What equilibrium exists in all aqueous solutions?
Equilibrium in water where a few molecules dissociate into protons and hydroxide ions
What is the equation of the equilibrium constant for the dissociation of water?
Kc = [H+][OH-]/[H₂O]
Concentration of water is constant
Kw = [H+][OH-]
What is the product of the two ion concentrations in Kw = [H+][OH-]?
1 x 10⁻¹⁴ mol² dm⁻⁶
Is a solution acidic or alkaline in there is higher concentration of [H+] than [OH-]?
Alkaline
Is a solution acidic or alkaline in there is higher concentration of [OH-] than [H+]?
Acidic
Is dissociation of water exothermic or endothermic?
Endothermic
How does temperature increase affect Kw?
Forward reaction will be favoured to counteract change and lower temperature
Shift right means more H+ and OH- form causing Kw to increase
What happens to value of pH when Kw increases?
Decreases
What are strong bases?
Basely completely ionised in solution
What is the equation for strong bases in solution?
BOH (aq) → B+ (aq) + OH- (aq)
Why do strong alkalis have small amounts of H+ in solution?
Ionisation of water
How can the pH of a strong alkali be found?
pH = -log[H+]
