Question

Students find that water can be created in a lab by burning hydrogen gas in air. They conclude that water is not a compound because only hydrogen is used to form the water. What is wrong with their conclusion?

Answer 1

Explanation:

Their conclusion is wrong because air is a mixture of many gases. The gas that combines with hydrogen to form the water is oxygen gas.

Hydrogen gas combines with oxygen gas to form water.

Water is made up of the elements hydrogen and oxygen.

• When hydrogen is burnt in air, the combustion is made possible due to the presence of oxygen gas.
• Together, the reaction produces water.
• Water is therefore a compound made up of hydrogen and oxygen