The equivalent weight of an unknown metallic element is . Its pure chloride salt is found to have a — Mole Concept and Some Basic Concepts of Chemistry Chemistry Question
Question
The equivalent weight of an unknown metallic element is $4$. Its pure chloride salt is found to have a vapour density of $59.25$. Determine the exact valency of this metallic element.
💡 Solution & Explanation
Step 1: Calculate the molar mass of the metal chloride. Molar mass = $2 \times \text{Vapour Density} = 2 \times 59.25 = 118.5\text{ g/mol}$. Step 2: Formulate the equation for molar mass. Let the valency of the element be $x$. The formula of the metal chloride will be $MCl_x$. Molar mass = (Atomic weight of M) + $(35.5 \times x)$. Step 3: Relate atomic weight to equivalent weight. Atomic weight = Equivalent weight $\times$ valency = $4x$. Step 4: Substitute and solve for $x$. $4x + 35.5x = 118.5 \Rightarrow 39.5x = 118.5 \Rightarrow x = 3$. The valency is 3.