EduNinja

[Maximum number: 1]

When calcium carbonate is heated strongly, a gas is given off.
Which word describes this change?

A

chemical

B

exothermic

C

physical

D

reduction

[Maximum number: 1]

Which equation represents a chemical change?

A

$\mathrm{BaCl}_{2}(\mathrm{~s}) \rightarrow \mathrm{BaCl}_{2}(\mathrm{I})$

B

$\mathrm{Ca}^{2+}(\mathrm{aq})+\mathrm{SO}_{4}{ }^{2-}(\mathrm{aq}) \rightarrow \mathrm{CaSO}_{4}(\mathrm{~s})$

C

$\mathrm{KCl}(\mathrm{s})+\mathrm{H}_{2} \mathrm{O}(\mathrm{l}) \rightarrow \mathrm{K}^{+}(\mathrm{aq})+\mathrm{Cl}^{-}(\mathrm{aq})$

D

$\mathrm{Na}^{+}(\mathrm{aq})+\mathrm{NO}_{3}{ }^{-}(\mathrm{aq}) \rightarrow \mathrm{NaNO}_{3}(\mathrm{aq})$

[Maximum number: 1]

Which row identifies a chemical change and a physical change?

chemical change

physical change

boiling ethanol

burning ethanol

evaporating ethanol

dissolving ethanol in water

burning ethanol

evaporating ethanol

dissolving ethanol in water

CAIE IGCSE Chemistry 6.1 Physical and Chemical Changes Topic Practice