When a candle burns, is it possible to get the wax back
(a) after the wax melts?
(b) after the wax burns?
(HINT: Are these phyusical changes or chemical changes?)

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Solution

Candle is a solid cylindrical block of wax with a wick embedded in it.
a) A candle starts melting when it comes in contact with the heat of the flame. The change in shape and size of the candle takes place. This indicates a physical change from solid state to liquid state. It is possible to get the wax back after it melts.
b) A wax candle acts as a fuel when we burn the candle. It is basically carbon. The wax oxidises (burns) in the flame to yield water and carbon dioxide, which dissipate in the air around the candle in a reaction, which also yields light and heat. The unburnt carbon is deposited as a black substance called soot. This signifies a chemical change. It is not possible to get the wax back after it burns.

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Similar questions

Q. Assertion :The burning of a candle is both a physical and a chemical change. Reason: Burning of candle melts the wax and hence physical state of wax has changed from solid to liquid. Again the wax combines with the atmosphere oxygen and changes to carbon dioxide, heat and light.

Q. Which of the following are physical changes and which are chemical changes ?
Burning of candle wax, Melting of candle wax, Mixing of iron filings and sand, Burning of wood, Breaking a piece of chalk, Burning a piece of paper, Cutting a piece of paper.

Q. Statement 1: Melting of candle wax is a physical change and the melted wax can again be obtained as solid wax upon the removal of heat.

Statement 2: Burning of candle wick is a chemical change and the wick cannot be obtained back in its original form.

Based on the given statements, choose the right option.

We observe that some portion of wax (in a candle) melts and another portion of it is used in producing heat and light.
Statement A: The melting of wax is a physical change
Statement B: The burning of wax for the production of heat and light is a chemical change.

Q. Why is the burning of a candle considered to be an irreversible change, even though we get back the wax after cooling it?

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When a candle burns, is it possible to get the wax back (a) after the wax melts? (b) after the wax burns? (HINT: Are these phyusical changes or chemical changes?)

When a candle burns, is it possible to get the wax back
(a) after the wax melts?
(b) after the wax burns?
(HINT: Are these phyusical changes or chemical changes?)