Which one among the following compounds has same equivalent weight and molecular weight ?

Equivalent weight is defined as the molar mass divided by the n-factor (valency factor) [1]. For acids, the n-factor is its basicity; for bases, its acidity; and for salts, it is the total positive or negative charge [1]. For equivalent weight to equal molecular weight, the n-factor must be 1. In H2SO4, the basicity is 2, making the equivalent weight half the molecular weight (98/2 = 49) [1]. In CaCl2, the total positive charge from Ca2+ is 2, so the equivalent weight is M/2. NaCl (sodium chloride) dissociates into Na+ and Cl-, carrying a total positive charge of 1 [1]. Therefore, for NaCl, the equivalent weight equals the molecular weight (M/1). Option 3 (Na^C^) appears to be a typographical error for sodium compounds like Na2CO3, which has an n-factor of 2.

Sources

1. [1] https://mlsu.ac.in/econtents/1844_SPOT%20I.pdf