Step-by-step explanation:
The given data is as follows.
= 1.5 atm,
= 20 L,
= (28 + 273) K = 301 K
= 5 atm,
= ?,
= (50 + 273) K = 323 K
Formula to calculate the volume will be as follows.
=

Putting the given values into the above formula as follows.
=
=
= 0.64 L
Thus, we can conclude that the change in volume of the balloon will be 0.64 L.