Question

Melting of canding wax is a ................ change but its burning is a ....................

Answer 1

Answer :

Melting of candle wax is a physical change but its burning is a chemical change.

Explanation:

When a candle wax is melted, it only changes its state from solid to liquid. It's hence a physical change as it can be reversed back to solid wax when cooled. Melting of wax involves no chemical changes.

But, on the other hand, when a candle is burnt, the wax which melts can be reversed back to solid wax again but, the wax present near the wick of the candle cannot to reversed back again. This is because the wick will absorb the liquid wax nearby to prolong the buring process of the candle. Hence, the liquid wax vaporizes and form new substances like carbon soot, carbon dioxide, etc. Hence, it's a chemical change (irreversible).

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Additional Information:

Physical change:-

• A physical change is a type of change which can be reversed back. It only involves a temporary change in the physical properties of a particular substance.
• No new substance is formed during a physical change.

Chemical change:-

• A chemical change is a type of change which is irreversible. It involves permanent changes it the chemical properties & composition of a particular substance.
• At least one new substance is formed during a chemical change.

Answer 2

Answer:

Melting of candle wax is a physical change but its burning is a chemical change.

Explanation:

When a candle wax is melted, it only changes its state from solid to liquid. It's hence a physical change as it can be reversed back to solid wax when cooled. Melting of wax involves no chemical changes.

But, on the other hand, when a candle is burnt, the wax which melts can be reversed back to solid wax again but, the wax present near the wick of the candle cannot to reversed back again. This is because the wick will absorb the liquid wax nearby to prolong the buring process of the candle. Hence, the liquid wax vaporizes and form new substances like carbon soot, carbon dioxide, etc. Hence, it's a chemical change (irreversible).

Additional Information:

Physical change:-

A physical change is a type of change which can be reversed back. It only involves a temporary change in the physical properties of a particular substance.

No new substance is formed during a physical change.

Chemical change:-

A chemical change is a type of change which is irreversible. It involves permanent changes it the chemical properties & composition of a particular substance.

At least one new substance is formed during a chemical change.