Why do real gases deviate from gas laws

Which statement about the stamps is correct?

Which change in temperature is the smallest? a change of 1 thomson degree a change of 1 kelvin degree a change of 1 fahrenheit degree a change of 1 celsius degree

Given the following at 25c calculate delta hf for hcn (g) at 25c. 2nh3 (g) +3o2 (g) + 2ch4 (g) > 2hcn (g) + 6h2o (g) delta h rxn= -870.8 kj. delta hf=-80.3 kj/mol for nh3 (g), -74.6 kj/mol for ch4, and -241.8 kj/mol for h2o (g)