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All bases tend to feel
slippery like soapCLEANING FLUID ▶
The strongest bases have a
pH of 14 or more. Alkaline
solutions with a high pH are
used as cleaning materials as
they dissolve fats. Cleaning fluids
such as bleach and caustic soda
have a pH of around 10.LIQUID SOAP ▶
Soap is a weak base. It is
made by combining a
weak acid with a strong
base, making it only
mildly alkaline with a pH
of about 8. An indicator
paper dipped into liquid
soap turns blue.LIMESTONE ▶
Calcium carbonate, or
limestone, is a type of rock
formed from the remains of
dead sea creatures over millions
of years. It is an important base,
which is quarried and crushed
to make fertilizers, paints,
ceramics, and cement.HYDRANGEAS ▶
The hydrangea shrub
produces different coloured
flowers depending on the
acidity of the soil. On acid
soils, it produces blue
flowers, on alkaline soils, it
produces pink or purple
flowers, and on neutral soils,
it has creamy white blooms.Water
Pure water is neither acid nor
alkali, but neutral, with a pH of 7.
Rainwater is slightly acidic, with a
pH of 5 to 6, while seawater is slightly
alkaline, with a pH of between 8 and 9.The pH of tap water is usually
between 6 and 8 depending
on the gases and minerals
that are dissolved in it094_095_AcidsBases.indd 95 03/01/19 12:10 PM