The new volume is 330.2 ml
calculation
The new volume is calculated using the Charles law formula
that is V1/T1= V2/T2
where T1= 25.0 c into kelvin = 25 +273 = 298 K
V1= 300.0 ml
T2 = 55.0 c into kelvin = 273 +55 =328 K
V2 = ? ml
make V2 the subject of the formula by multiplying both side by T2
V2= V1T2/ T1
V2 =[ (300.0 ml x 328 k) / 298 k} = 330.2 ml