Importance of Chemical Changes

When we add water to the following substances. Which one will show a chemical change? 

A pop sound is heard when a lighted match stick is brought near the mouth of a jar. This indicates the release of gas:

When sugar is heated its colour changes into

The compound rust is a hydrated oxide of

The burning of sugar is a temporary change.

Rusting of iron is a chemical change.

State whether the following is a physical or chemical change.

Slaking of lime.

State whether the following is a physical or chemical change.

Boiling of an egg.

State whether the following is a physical or chemical change.

Melting of wax.

State whether the following is a physical or chemical change.

State whether the following is a physical or chemical change.

Photosynthesis.

State whether the following is a physical or chemical change.

Lightning.

State whether the following is a physical or chemical change.

Growing of a piglet into a pig.

State whether the following is a physical or chemical change.

Burning of sugar

Burning of fuel is a _____ change.

Name a chemical change that takes place in presence of electricity.

Name a chemical change which takes place in presence of light.

Name a chemical change which takes place in presence of heat.

What do you observe when a little amount of curd is added to a bowl containing warm milk and kept for five hours? 

What do you observe when a quick lime is dissolved in water?