Question

The chemical equations are balanced to satisfy one of the following laws in chemical reactions. This law is known as:

• A. law of conservation of mass
• B. law of conservation of motion
• C. law of conservation of momentum
• D. law of conservation of magnetism

Answer 1

The correct option is A

law of conservation of mass

Explanation for correct answer:-

Option (A) law of conservation of mass:

• The Law of conservation of mass states that mass can neither be created nor be destroyed.
• It can only be transformed from one form to another.
• The various chemical reactions are basically represented by the chemical equations.
• In the equations, the Reactants are kept on the left side and the products are kept on the right side.
• Let us take an example of a reaction of hydrogen with oxygen which produces water:

$\underset{\mathrm{Hydrogen}}{{\mathrm{H}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\to \underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$

• Here we can see that there are 2 hydrogen atoms on the right side and 2 hydrogen atoms on the left side.
• But there is only 1 oxygen atom on the right side but 2 oxygen on the left side, so we need to balance it.
• If we multiply the hydrogen by 2 and the water by 2 then the reaction would be balanced:

$\underset{\mathrm{Hydrogen}}{2{\mathrm{H}}_2\left(\mathrm{g}\right)}+\underset{\mathrm{Oxygen}}{{\mathrm{O}}_2\left(\mathrm{g}\right)}\to 2\underset{\mathrm{Water}}{{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right)}$

• Now the equation is balanced, thus it satisfies the law of conservation of mass.
• This is because the mass of the reactants has to be equal to the mass of the products, which will obey this law.
• Hence it is the correct option.

Therefore, The chemical equations are balanced to satisfy one of the following laws in chemical reactions. This law is known as option (A) law of conservation of mass.