A balloon of 21 cm diameter is to be filled with hydrogen gas at S.T.P. from a cylinder containing hydrogen gas at 20 atm and 300 K. The capacity of the cylinder is 2.82 litres at S.T.P. How many balloons can be filled in ?

Explanation

To solve the problem step by step, we will follow these calculations:

### Step 1: Calculate the Volume of the Balloon
The volume \( V \) of a sphere (balloon) is given by the formula:
\[ V = \frac{4}{3} \pi r^3 \]
where \( r \) is the radius of the balloon.
...