Chemistry - acids and bases (chemical changes)

What is meant by a weak acid?

• do not ionise fully in water

• small proportion of acid particles release H+ ions

What is meant by a strong acid?

• ionise completely in water

• all acid particles release H+ ions

all acids form ___ ions in aqueous solutions

H+

all alkali form ___ ions in aqueous solutions

OH-

which indicator can measure pH? what is the positive result for acidic?

• universal indicator

• red/ orange

what does it mean if a solution is pH 7?

it is neutral

what does it mean if a solution is less than pH 7?

it is acidic

what does it mean if a solution is greater than pH 7?

it is alkali

which colours do the following produce in universal indicator;

weak alkalis and strong alkalis

• weak; blue

• strong; purple

which colours do the following produce in universal indicator;

weak acids and strong acids

• weak; yellow

• strong; red/ orange

which colour do neutral solutions produce in universal indicator?

green

equation for neutralisation between an acid and alkali/ base

H+(aq) + OH-(aq) → H₂O(l)

state 3 examples of weak acids

ethanoic, citric and carbonic acid

dilute

a solution with a small amount of solute compared to the solvent

concentrated

a solution with a large amount of solute compared to the solvent