When dissolved in dilute sulphuric acid, 0.275 g of a metal evolved 119.7 mL of hydrogen at 20°C and 763 mm pressure. What is the equivalent mass of the metal ?

Explanation

To find the equivalent mass of the metal, we will follow these steps:

### Step 1: Calculate the moles of hydrogen gas evolved.

We will use the ideal gas law formula:
\[ PV = nRT \]
...