Heat is given off when hydrogen burns in air according to the equation:
2H2 + O2 ---> 2H2)
What is responsible for the heat?
I know the answer is froming hydrogen-oxygen bonds gives off energy, but why?
Your answer is close but not quite there I don't think. It takes energy to break the H-H bond and it takes energy to break the O-O bond. Forming the O-H bond produces energy. The sum of forming 4-OH bonds is greater than breaking 2 H-H bonds and 1 O-O bond; therefore, the reaction is exothermic.
The heat released during the burning of hydrogen in air is due to the formation of new chemical bonds between hydrogen and oxygen atoms. In the given equation, two molecules of hydrogen gas (H2) react with one molecule of oxygen gas (O2) to form two molecules of water vapor (H2O).
During this reaction, the hydrogen atoms in the hydrogen gas molecules bond with the oxygen atoms in the oxygen gas molecule to form new chemical bonds in the water vapor molecules. This process involves the breaking of the existing bonds within the hydrogen and oxygen gas molecules, followed by the formation of stronger chemical bonds in the water molecules.
The formation of chemical bonds is an exothermic process, meaning it releases energy. In the case of hydrogen and oxygen, the formation of water molecules releases a significant amount of energy in the form of heat.
This release of energy occurs because the chemical bonds in water are more stable and have lower energy compared to the bonds in hydrogen and oxygen gases. As a result, the excess energy is released into the surroundings as heat.
Overall, the heat generated during the burning of hydrogen in air is a result of the release of energy during the formation of new, more stable chemical bonds in water molecules.
The heat released during the combustion of hydrogen in air is attributed to the formation of hydrogen-oxygen bonds in the reaction. To understand why these bonds release energy, we need to look at the concept of bond energy.
In a chemical reaction, bonds between atoms are either broken or formed. Breaking a bond requires an input of energy, while forming a bond releases energy. This energy is known as bond energy or bond enthalpy.
In the given equation, two molecules of hydrogen (H2) react with one molecule of oxygen (O2) to produce two molecules of water (H2O). During this process, the existing bonds in the reactant molecules are broken, and new bonds are formed to create the product molecules.
In particular, two hydrogen-oxygen (H-O) bonds are formed in each water molecule during this reaction. The formation of these bonds releases energy, which subsequently manifests as heat. This energy release occurs because the bonds formed are in a more stable configuration than the bonds that were broken in the reactant molecules.
Overall, the combustion of hydrogen in air releases heat due to the formation of more stable hydrogen-oxygen bonds in water molecules. The energy released during bond formation is responsible for the heat observed during the reaction.