AIIMS 2010 Chemistry Ionic Compounds MCQ Question

To determine the formula of the chloride of the metal represented as M in the phosphate MHPO₄, we first analyze the composition of the phosphate. In this compound, M is a metal that combines with one phosphate ion (HPO₄) which has a charge of -2. Therefore, to balance the charges, M must have a +2 charge.

When forming chlorides, the metal M will combine with chlorine (Cl), which typically has a -1 charge. To balance the +2 charge of M, we need two chloride ions. Thus, the formula for the chloride will be MCl₂.

Let's analyze the other options:

• A) MCl: This would imply that M has a +1 charge, which does not balance with the -1 charge from one Cl.
• C) MCl₃: This would imply that M has a +3 charge, which is not consistent with the +2 charge deduced from the phosphate.
• D) M₂Cl₃: This suggests the presence of two M atoms, which is unnecessary since one M atom can balance with two Cl atoms.

Thus, the correct answer is B) MCl₂.