Acids and bases Flashcards
what is an acid
proton donor
what is a base
proton acceptor
what is a strong acid
an acid which fully dissociates
what is a weak acid
an acid which only partially dissociates
equation for pH
pH= -Log10 [H+]
ionic product of water equation
kw=[H+][OH-]
equation for the pH of a strong acid
pH= -Log10 [H+]
equation for a weak acid
square root (Ka x conc)
acid + metal products
salt + hydrogen
acid and metal oxide products
salt + water
acid + metal hydroxide products
salt + water
acid + metal carbonate products
salt + CO2 + water
types of strong acids
HCl
H2SO4
HNO3
H3PO4
types of weak acids
methanoic acids
ethanoic acids
propanoic acid
what is a Buffer
is a solution which can resist changes in pH when a small amount of acid or base is added
types of strong bases
NaOH
KOH
Ca(OH)2
types of weak bases
NH3
phenylamine
Steps of acid base titrations without pH probe
- Fill a burette with the acid of a know concentration
- Accurately measure out 25cm3 of the alkali standard solution using a pipette and transfer to a conical flask
- Add a few drops of a suitable indicator to the alkali
- Slowly add the acid from the burette into the conical flask, swirling constantly. As soon as the indicator changes colour the solution has turned neutral so stop adding the acid
- Record the volume of acid which has been added.
- Repeat the process until you get two results which are within 0.1cm3 of each other. The mean of these two results are then used to calculate an average titre.
steps of acid base titrations with a pH probe
- Measure the pH of the acid solution and record
- Add 1cm3 of the base solution
- Stir the mixture
- Measure the pH and record
- repeat the process until the base is in excess
- Add base in smaller increments near the end point
