weak

diluted

concentrated

strong

the point during titration when the

reaction is nearly complete

a chemical substance that changes colour at the endpoint

Methyl red

Phenolphthalein

Methyl orange

loses electrons and is oxidised.

gains electrons and is reduced.

gains electrons and is oxidised.

loses electrons and is reduced.

MnO₄^- + 8H⁺ + 5e →  Mn²⁺ 4H₂O

MnO₄^- + 8H⁺ + 8e →  Mn²⁺ 4H₂O

2MnO₄^- + 8H⁺ + 5e →  2Mn²⁺ 4H₂O

MnO₄^- + 5H⁺ + 5e →  Mn²⁺ 4H₂O

+5

-5

+7

-7

light rose colour

pale yellow

purple

colourless

to produce oxygen and water

to produce carbon

dioxide and water

to produce carbon dioxide and oxygen

none of these

Methyl red

Potassium permanganate

No indicator

Methyl orange

2/5

1/5

1/2

5