An air-filled balloon has a volume of 225 l at 0.940 atm and 25 °c. soon after, the pressure changes to 0.990 atm and the temperature changes to 0 °c. what is the new volume of the balloon?

The right choice is  V₂ = 195.7 L

Explanation:

where, P is the pressure of the gas in atm.

V: is the volume of the gas in L.

n: is the no. of moles of the gas in mol.

R:  is the general gas constant,

T: is the temperature of the gas in K.

If n is constant, and have different values of P, V and T:

(P₁*V₁) / T₁ = (P₂ * V₂) / T₂

Knowing that:  

V₁  =  225 L  ,         P₁ = 0.940 atm

T₁ = 25  °C + 273  =  298 K

V₂  =  ??? L,           P₂ = 0.990 atm  

T₂ = 0 °C + 273  =  273 K

applying in the above equation

(P ₁* V₁) / T₁ = (P₂ * V₂) / T₂

(0.940 atm * 225 L) / 298 K= (0.990 atm  * V₂) / 273 K

V₂ = (0.940 atm * 225 L * 273 K) / (298 K * 0.990 atm)

V₂ = 195.7 L

So, the right choice is:

V₂ = 195.7 L