WHAT HAPPENS WHEN A CANDLE BURNS IN A FIXED VOLUME OF AIR?

Half fill a water trough with sodium hydroxide solution. Stick a candle on a beehive shelf and place it in the trough containing sodium Hydroxide.Cover the candle with a graduated gas jar. Mark the level of the solution in the jar. Record the volume.Light the candle. Cover it slowly with the graduated gas jar. Observe how the level of the solution changes.