First divide 451g by kryptons molar mass
451g/84gmol= 5.369047619moles
Then multiply 5.369047619moles by 22.4L(volume 1 mol of a gas occupies at STP)
5.369047619moles x 22.4L= 120.26L
Answer: 120.26L
Hoped this helped to explain molar conversions it can be hard to understand at first but you will get the hang of it