Statement I: Chemical equivalent of Mg is half of its atomic weight

Statement II: Charge present on Mg is +2

Both Statement I and Statement II are correct and Statement II is the correct explanation of Statement I

The correct answer is option 1. Both Statement I and Statement II are correct and Statement II is the correct explanation of Statement I.

Let us delve deeper into each statement and their relationship:

Statement I: Chemical equivalent of Mg is half of its atomic weight

The chemical equivalent of an element is defined as the atomic weight of the element divided by its valency (or combining power). It represents the amount of the substance that reacts with or is equivalent to one mole of hydrogen ions \((H^+)\) or hydroxide ions \((OH^-)\) in a chemical reaction.

For magnesium \((Mg)\), the atomic weight (or atomic mass) is approximately 24.305 atomic mass units \((amu)\).  Magnesium typically forms ions with a charge of +2. This means each magnesium atom loses two electrons to achieve a stable noble gas electron configuration (similar to neon). As a result, the valency (or charge) of magnesium ions \((Mg^{2+})\) is +2.

To determine the chemical equivalent of magnesium, we use the formula:

\(\text{Chemical equivalent} = \frac{\text{Atomic weight}}{\text{Valency}}\)

Substituting the values for magnesium:

\(\text{Chemical equivalent} = \frac{24.305 \text{ amu}}{2} = 12.1525\)

Therefore, the chemical equivalent of magnesium is approximately 12.1525 grams per mole. This means that 12.1525 grams of magnesium will react with one mole of hydrogen ions \((H^+)\) or hydroxide ions \((OH^-)\).

Statement II: Charge present on Mg is +2

Magnesium \((Mg)\) is a metal located in group 2 of the periodic table. Metals in group 2 typically form cations with a 2+ charge. This is because they readily lose two electrons from their outer shell to achieve a stable electron configuration similar to a noble gas (in this case, magnesium forms \(Mg^{2+}\) ions).

The charge of +2 on magnesium ions \((Mg^{2+})\) indicates that each magnesium ion has lost two electrons. This gives it a net positive charge of +2.

Explanation of the Relationship:

Statement II provides the correct explanation for Statement I. The chemical equivalent of magnesium being half of its atomic weight arises directly from its valency (charge). Since magnesium typically forms \(Mg^{2+}\) ions, the chemical equivalent is indeed calculated as half of its atomic weight divided by 2. This is because each mole of Mg reacts with twice the number of equivalents of hydrogen ions (or hydroxide ions) compared to its atomic weight, due to its 2+ charge.

Therefore, Statement II explains why Statement I is true. The valency of magnesium being +2 directly determines its chemical equivalent, which is half of its atomic weight. In conclusion, both Statement I and Statement II are correct, and Statement II provides the correct explanation for why Statement I is true. Hence, the correct option is: Both Statement I and Statement II are correct and Statement II is the correct explanation of Statement I.