that seems very false but I believe its the second one
2H2O = 2H2 + O2.
<h3><u>Explanation</u>:</h3>
Balancing equations is very essential because of the fact that it represents the stoichiometric quantities of the reactants needed to react to form the product. The ratio of the weights of reactant and product are also very well understood from this.
Here in this equation, the water is broken into hydrogen and oxygen. The balanced reaction is
2H2O = 2H2 + O2.
Two moles of water is broken down into 2 moles of hydrogen and one mole of oxygen.
Chemical equations are to be balanced to be able to follow the law of conservation of mass where it says that mass cannot be created or destroyed. Reactions should be that the mass of the reactants is equal to the mass of the products.