A bivalent metal has 37.2 equivalent weight. The molecular weight of its chloride is

Options

A. 216.6
B. 148.8
C. 145.4
D. 172.8

Explanation

To find the molecular weight of the chloride of a bivalent metal with an equivalent weight of 37.2 g/equiv, we can follow these steps:

### Step 1: Determine the Atomic Weight of the Metal
The relationship between atomic weight (A), valency (V), and equivalent weight (E) is given by the formula:
\[ A = V \times E \]

Given that the metal is bivalent, its valency (V) is 2. The equivalent weight (E) is provided as 37.2 g/equiv.

Substituting the values:
\[ A = 2 \times 37.2 = 74.4 \text{ g/mol} \]

### Step 2: Write the Formula for the Chloride
Since the metal is bivalent, the formula for its chloride will be:
\[ \text{MCl}_2 \]
where M represents the bivalent metal.

### Step 3: Calculate the Molecular Weight of the Chloride
The molecular weight of the chloride can be calculated using the formula:
\[ \text{Molecular Weight of MCl}_2 = \text{Atomic Weight of M} + 2 \times \text{Atomic Weight of Cl} \]

We have already calculated the atomic weight of M as 74.4 g/mol. The atomic weight of chlorine (Cl) is approximately 35.5 g/mol.

Substituting the values:
\[ \text{Molecular Weight of MCl}_2 = 74.4 + 2 \times 35.5 \]
\[ = 74.4 + 71.0 \]
\[ = 145.4 \text{ g/mol} \]

### Final Answer
The molecular weight of the chloride is **145.4 g/mol**.

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