Acid Base equilibira Topic 12

Bronstead-Lowry Acids

Proton donors, release hydrogen ions

Bronsted-Lowry Bases

Proton acceptors, accept hydrogen ions

Standard Enthamphy Change of neutralisarion

Enthalpy change when solution of an acid and a base react together under standard conditions to produce 1 mole of water

pH

pH=-log[H+]

Calibrate pH meter

Place bulb in demonised water, adjust reading so it reads 7.0

Repeat with solution of pH 4 and pH 10

Diluting Strong acid

Increase pH by 1

Diluting Weak acid

Increase pH by 0.5

Methyl Orange Range and Colour

3.1 - 4.4

Red to Yelloe

Phenolphalein pH and Colour

8.3 - 10

Colourless To pink

Buffer

A solution that minimises changes in pH when small amounts of acids or base are added

Acidic buffer

Use weak acid and salt of its conducted base

Or excess weak acid with strong base

Alkaline buffer

Weak base and its salt

Henderson-Hasselbalch Equation for specific pH buffer

pH=pKa + log(([A]-)/(Ha))

Assuming that [HA]initial= [HA]start

Assuming that [A-]initial = [A-] start