Answer
a) $271\ mL$
b) No.
Work Step by Step
Mass of the soft drink, assuming it has water properties:
$m=\rho V=0.997\ g/cm^3\times250.cm^3=249\ g$
Volume occupied by this mass when frozen:
$V=m/\rho=249\ g \div 0.917\ g/cm^3 = 271\ cm^3=271\ mL$
Since this volume is bigger than the volume of the can, it cannot be contained by it.
