Final answer:
The equation 2 H2O(l) = 2 H2(g) + O2(g) is already balanced with a 2:1:2 molar ratio, meaning four hydrogen atoms and two oxygen atoms are present on each side, complying with the law of conservation of matter.
Step-by-step explanation:
The chemical equation provided by the student, 2 H2O(l) = 2 H2(g) + O2(g), is already correctly balanced. When balancing chemical equations, it is essential to ensure that the number of atoms for each element is the same on both sides of the equation. This process is done to satisfy the law of conservation of matter.
For the equation 2 H2O(l) → 2 H2(g) + O2(g), there are four hydrogen atoms and two oxygen atoms on both sides of the equation, maintaining the balance. Every balanced chemical equation represents both molecular and molar equivalences. In this case, the equation can be read as 'two moles of water decompose to produce two moles of hydrogen gas and one mole of oxygen gas.'
As a useful convention, chemical equations are written using the lowest whole-number coefficients, and this particular equation follows that principle with a 2:1:2 molar ratio.