2. Acidic, Alkaline & Neutral Substances

Acidic, Alkaline and
Neutral Substances

Science Year 3
Theme 4 Material Science

Presented By: Miss Ee

8.1.2
Make generalisation on acidic, alkaline and neutral
substances through taste and touch by testing a few
substances.

8.1.4
Explain the result of observations about acid and
alkali through written or verbal forms, sketches or
ICT in a creative way.

Besides changes in colour of the litmus
paper, the properties of substances can also
be determined through taste and touch.

Acidic • Most acidic
substances substances taste sour.

• Have a burning
sensation when
touched (corrosive).

• Examples of acidic
food substances:

Alkaline • Most alkaline
substances substances taste
bitter.

• Feel slippery and
smooth when touched.

• Examples of alkaline
food substances:

Neutral • Neutral substances
substances have different tastes
such as tasteless,
sweet and salty.

• May feel slippery or
coarse when touched.

• Examples of neutral
food substances:

What about coffee?

Coffee tastes bitter but when
it’s tested with blue litmus

paper, the colour changes to red.

Bitter substances are not always alkaline
and sour substances are not always acidic.

Can the senses of taste and
touch be used as indicators for

acidic, alkaline and neutral
substances? Why?

The acidic, alkaline and neutral
properties of a substance can
also be tested using the senses
of taste and touch, although

these are not scientific
indicators.



Substance Taste Touch Change in Property of
litmus paper substance

Fresh milk Slightly Slippery Blue→ Blue Neutral
sweet Red→ Blue
Neutral
Salt solution Salty Coarse Blue→ Blue Acidic
Red→ Red

Ketchup Sour Blue→ Red
Red→ Red
Slippery

Substance Taste Touch Change in Property of
litmus paper substance

Grapes Sour / Slippery Blue→ Red Acidic
sweet Red→ Red
Alkaline
Eggs white Tasteless Slippery Blue→ Blue Alkaline
Red→ Blue

Toothpaste - Slippery Blue→ Blue
Red→ Red

Most acidic substances taste sour.
Most alkaline substances taste bitter and feel
slippery when touched.
Neutral substances have different tastes such as
tasteless, sweet and salty, may feel slippery or
coarse when touched.