Water is formed when hydrogen and oxygen react with each other
The correct answer and explanation is:
Correct Answer:
Water is formed when hydrogen gas (H₂) reacts with oxygen gas (O₂) in a chemical reaction called combustion or synthesis. The balanced chemical equation for this reaction is: 2H2+O2→2H2O2H_2 + O_2 \rightarrow 2H_2O
This means two molecules of hydrogen gas react with one molecule of oxygen gas to produce two molecules of water (H₂O).
Explanation (300 words):
Water formation is a classic example of a chemical reaction between hydrogen and oxygen gases. Both hydrogen and oxygen are diatomic molecules, meaning they naturally exist as pairs of atoms (H₂ and O₂). When these gases combine under the right conditions—usually in the presence of a spark or flame—they undergo a highly exothermic reaction, releasing energy in the form of heat and light.
The reaction involves breaking the bonds between the hydrogen atoms in H₂ and the oxygen atoms in O₂. When these bonds break, the atoms rearrange to form new chemical bonds in water molecules. Each water molecule contains two hydrogen atoms covalently bonded to one oxygen atom (H₂O).
The balanced chemical equation: 2H2+O2→2H2O2H_2 + O_2 \rightarrow 2H_2O
shows the stoichiometric relationship where two molecules of hydrogen react with one molecule of oxygen to form two molecules of water. Balancing ensures the law of conservation of mass is obeyed, meaning atoms are neither created nor destroyed during the reaction—just rearranged.
This reaction is also an example of a combustion reaction, often called an oxidation-reduction (redox) reaction. Oxygen acts as the oxidizing agent, gaining electrons, while hydrogen is the reducing agent, losing electrons.
Because the reaction releases a lot of energy, it is used in fuel cells and rockets where hydrogen is burned in oxygen to produce water vapor and thrust.
In summary, water is formed through a chemical reaction where hydrogen and oxygen molecules combine to make water molecules, releasing energy. This fundamental reaction highlights the transformation of elements and the conservation of mass in chemical processes.