MCQ Detailed View

Balancing chemical equations is an essential skill in chemistry. It ensures that the law of conservation of mass is followed, meaning the number of atoms of each element is the same on both sides of the reaction. The easiest and most widely accepted method for balancing is a stepwise approach: balance the metals first, then the non-metals, followed by hydrogen, and finally oxygen.

Metals are usually balanced first because they are less likely to change places in reactions. Non-metals are considered next since they often form stable compounds that remain unchanged in the reaction. Hydrogen is balanced after metals and non-metals because it is commonly present in acids, bases, and water, making it easier to adjust at this stage. Oxygen is left for last because it frequently appears in multiple compounds on both sides of the equation, and adjusting it at the end simplifies the process.

Balancing by atomic number or atomic mass is incorrect. Atomic number represents the identity of an element, and atomic mass shows its relative weight. Neither of these helps in balancing a reaction because balancing depends on coefficients (the number of molecules), not the properties of individual atoms. The correct method is to adjust the coefficients so that the total number of atoms for each element remains equal on both sides.

This stepwise method is especially important in combustion reactions, redox reactions, and acid-base neutralization. For example, in the combustion of methane, metals are absent, so carbon is balanced first, hydrogen next, and oxygen last. Following this order avoids confusion and reduces the chance of errors.

Therefore, the easiest and most systematic way to balance chemical equations is by arranging the sequence: metal → non-metal → hydrogen → oxygen. This approach ensures accuracy and clarity in chemical calculations.