Question

Balloons of $4L$ capacity are to be filled with hydrogen at a pressure of $1$ atm and ${27}^0$C from an $8L$ cylinder containing hydrogen at $10$ atm at the same temperature. The number of balloons that can be filled is:

• A. $20$
• B. $18$
• C. $40$
• D. $38$

Answer 1

The correct option is A $20$

Given:

Volume of balloons = 4 L

Pressure of Balloons = 1 atm

Volume of cylinder = 8 L

Pressure of cylinder = 10 atm

Temperature is same for both balloons and cylinder.

Using ideal gas law, $PV=nRT$

where,

P = pressure, V = volume, T = temperature, n = number of moles, R = gas constant

At constant temperature, 'n' is directly proportional to the pressure and volume.

$n=PV$

Now we have to calculate moles of balloons and cylinder.

For balloons :$n_b=1atm\times 4L=4$

For cylinder :$n_c=10atm\times 8L=80$

Now we have to calculate the number of balloons that can be filled.$\frac{n_c}{n_b}=\frac{80}{4}=20$

The number of balloons that can be filled = 20