2 gm of a base whose equiv wt. is 40 reacts with 3 gm of an acid. The equiv wt. of the acid is -

Options

A. 40
B. 60
C. 10
D. 80

Answer

To find the equivalent weight of the acid that reacts with 2 g of a base (equivalent weight = 40) and 3 g of the acid, we can follow these steps:

### Step 1: Understand the concept of equivalents
In a neutralization reaction between an acid and a base, the number of equivalents of the acid will equal the number of equivalents of the base.

### Step 2: Calculate the number of equivalents of the base
The number of equivalents of the base can be calculated using the formula:
\[ \text{Number of equivalents} = \frac{\text{mass of the substance (g)}}{\text{equivalent weight (g/equiv)}} \]
For the base:
\[ \text{Number of equivalents of base} = \frac{2 \, \text{g}}{40 \, \text{g/equiv}} = 0.05 \, \text{equiv} \]

### Step 3: Set up the equation for the acid
Since the number of equivalents of the acid will equal the number of equivalents of the base, we can set up the equation:
\[ \text{Number of equivalents of acid} = \text{Number of equivalents of base} = 0.05 \, \text{equiv} \]

### Step 4: Calculate the equivalent weight of the acid
Using the formula for the number of equivalents for the acid:
\[ \text{Number of equivalents of acid} = \frac{\text{mass of acid (g)}}{\text{equivalent weight of acid (g/equiv)}} \]
Substituting the known values:
\[ 0.05 \, \text{equiv} = \frac{3 \, \text{g}}{\text{equivalent weight of acid}} \]

### Step 5: Rearranging to find the equivalent weight of the acid
Rearranging the equation gives us:
\[ \text{equivalent weight of acid} = \frac{3 \, \text{g}}{0.05 \, \text{equiv}} = 60 \, \text{g/equiv} \]

### Final Answer:
The equivalent weight of the acid is **60 g/equiv**.

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