Question

if 20 grams of methane is burnt then how much amount of CO2 is released

Answer 1

reaction of methane In air is -----

CH4 +2O2--------->CO2+2H2O
here you see 1 mole CH4 form 1mole CO2 after burning.
hence,
16g CH4 formed 44g CO2 after burning
so,
20g CH4 formed 44/16 x 20=55g CO2

hence 55g CO2 formed .