AC18: pH Flashcards
What is the equation to find pH
-log10[H+]
- Minus log base 10 [proton concentration]
What is the general ka formula before the assumptions
[products] / [reactants]
What is the pKa formula
pKa = -log10(Ka)
What is the equation for Ka, when you have pKa
10 ^-pKa
If a pKa is smaller, is the acid stronger or weaker
Stronger
If a Ka is bigger is the acid stronger or weaker
Stronger
What is the formula for Ka, after assumptions
Ka = [H+]^2 / [acid]
What is the equation for pH if the acid is a weak acid
pH = -log10 (squareroot) Ka x [acid]
What are the 2 assumptions made when using the Ka formula
- The concentrations of the products are the same
- The equilibrium lies so far left the concentration of reactant doesn’t change during the reaction
What is the definition of neutral water
Number of H+ is equal to the number of OH-
Is the ionisation of water endothermic or exothermic
Endothermic
When the temperature increases, does the ionisation of water equilibrium shift right or left
Shifts right in the endothermic reaction
What is the pH equation of a buffer solution
-log10 (kA x [acid] / [salt])
In buffer solutions, what is pH ideally equal to
pKa
What is the inequality for pH of a buffer solution
pKa -1 < pH < pKa +1
What is the blood buffer equation
H2CO3 +H2O -> HCO3- + H3O+
What is the Kw equation
Kw = [H+][OH-]
What is the value of kW
10^-14
