Why is balanced chemical equation for H2O written 2H2+0>2H20 and not H20>H20?
First it isn't written
2H2 + O --> 2H2O but as
2H2 + O2 ==> 2H2O for the FORMATION of water.
Whereas, H2O ==> H2O isn't telling you how the water was formed from the elements.
You could have something like
H2O(l) ==> H2O(g) where l stands for liquid and g stands for gas.
The balanced chemical equation for the formation of water (H2O) is written as 2H2 + O2 → 2H2O, not simply H2O → H2O. This equation represents the balanced combination of hydrogen gas (H2) and oxygen gas (O2) to form water.
The reason we need to balance the equation is to ensure that the number of atoms of each element remains equal on both sides of the equation. Subscripts are used to indicate the number of atoms of each element in a molecule.
In the case of water, on the left side of the equation, we have two hydrogen molecules (H2), which means we have a total of 4 hydrogen atoms (2 molecules × 2 atoms/molecule). On the right side of the equation, we have two water molecules (H2O), which also contain 4 hydrogen atoms (2 molecules × 2 atoms/molecule).
However, when we look at the oxygen atoms, we have two oxygen atoms in an oxygen molecule (O2) on the left side of the equation. On the right side, we have four oxygen atoms from the two water molecules (2 molecules × 2 atoms/molecule).
To balance the equation, we need to add a coefficient of 2 in front of the water molecule (H2O), resulting in 2H2 + O2 → 2H2O. This adjustment ensures that the number of oxygen atoms is the same on both sides of the equation (2 atoms on both sides).
By balancing the equation, we maintain the law of conservation of mass, which states that matter cannot be created or destroyed in a chemical reaction. Therefore, the balanced equation accurately represents the chemical reaction where hydrogen gas (H2) combines with oxygen gas (O2) to produce water (H2O).