Question

A spherical balloon initially contains 1 mole air at 1 atm, then it is further filled with air till pressure increases to 3 atm. The initial diameter of the balloon is 1 m and the pressure at each state is directly proportional to diameter of the balloon. Answer the following questions.(a) Find out number of moles of air added in balloon to change the pressure from 1 atm to 3 atm. (b) If balloon burst either pressure increases to 7 atm or volume increases to $360\pi m^3$.Calculate the number of moles of air that must be added after initial condition to burst the balloon.

• A. 2, 6
  
• B. 6, 2
  
• C. 5, 6
  
• D. 6, 5
  

Answer 1

The correct option is A 2, 6

(a) $n^{\prime }=n\times \frac{P^{\prime }}{P}=1\times \frac{3}{1}=3$
$\Delta n=n^{\prime }-n=3-1=2$
The number of moles of air added is 2.
(b) $n^{\prime }=n\times \frac{P^{\prime }}{P}=1\times \frac{7}{1}=7$
$\Delta n=n^{\prime }-n=7-1=6$"