Question

Describe an activity to show that candle burns giving out water vapour,carbon dioxide and soot

Answer 1

Answer:

An activity that demonstrates that soot, water vapour and carbon dioxide is formed on combustion is as follows:

Light a candle and fix it on the table and cover it with a glass chimney.

Put a glass plate over the chimney.

Let the candle burn till it is extinguished.

Observe the changes and presence of new substances in the chimney.

Collect the gas in the chimney and pass it through lime water.

The observations are:

Soot collects on the underside of the glass plate.

Water vapour condenses as droplets of water on the sides of the chimney.

The candle is extinguished as oxygen present is used up and is replaced by another gas. The gas turns lime water milky indicating that it is carbondioxide.