[Sec 2] Chemical Changes

Which option does not indicate chemical change?

• New substances are formed.

• Heat and/or light is usually given off.

• It can be separated by filtration.

• The change is irreversible.

sugar -> carbon + water vapour is an example of which type of chemical reaction?

• Thermal decomposition

• Oxidation

• Photosynthesis

• Electrolysis

In photosynthesis

(carbon + water -> glucose + oxygen + water),

the condition required for this reaction to take place is

• air

• heat

• light

• water

Which is not an acid?

• hydrochloric acid

• sulfuric acid

• sodium hydroxide

• nitric acid

The indicator shown in the picture is

• acid paper

• litmus paper

• coloured paper

• universal indicator

Which picture indicates an acid?

• 
• 

To test for presence of hydrogen gas, we use

• lighted splint

• glowing splint

• limewater

• universal indicator

To test for presence of carbon dioxide, we use

• lighted splint

• glowing splint

• limewater

• universal indicator

In a reaction of acid and base, what are the products formed?

• acid and base

• salt and water

• salt and hydrogen

• salt and carbon dioxide

In a reaction, salt and hydrogen gas are produced.

What are the reactants involved?

• salt and hydrogen

• acid and salt

• acid and reactive metal

• acid and base