Drinking candle

The water level rises up as the candle burns.

Scientific name: Oxygen supports burning. Water occupies the vacant volume.


CSAV Hawaii: Best Science Magic Trick Candle & Water

Состав воздуха

Water and Candle Science Project

by mrhappy0121

Under Water Candle - Cool Science Experiment | Mocomi Kids

by MocomiKids


Wear eye protection goggles.

Always follow general safety recommendations. Please note that conducting chemistry experiments you must comply with the relevant legal procedures in your country.

Reaction formula

C25H52 + 38O2 → 25CO2 + 26H2O


  1. Paraffin wax
  2. Water

Step-by-step instruction

  1. In this experiment the volume proportion of oxygen in air is determined.
  2. Put a floating candle into a beaker partially filled with water.
  3. Light the candle.
  4. Cover the floating candle with a graduated cylinder.
  5. The water level rises up as the candle burns.
  6. When candle goes out mark the level on which the water rose up.

Scientific background

Oxygen supports burning. Till there is some oxygen inside the cylinder the candle burns. Oxygen is consumed during combustion and water occupies the vacant volume. This volume corresponds to the volume fraction of oxygen in air. When the candle goes out the water will reach the mark of one fifth of the cylinder volume. Indeed the air we breathe consists of two main components. They are 21 % of oxygen and 79% of nitrogen.


Published on 09 September 2015

  • Fire
  • Heating with fire
  • Explosion
  • Poisoned gas
  • Organic
  • Electricity
  • Solution
  • Oxidation reduction
  • Color change
  • Precipitate
  • Gassing
  • Catalyst