What is the mass of potassium chloride produced when $$12.25 \mathrm{~g}$$ potassium chlorate undergo decomposition? (At mass: $$\mathrm{K}=39, \mathrm{Cl}=35.5, \mathrm{O}=16$$ )

Which from following formulae is a correct formula to determine percent atom economy?

What is the volume (in dm$$^3$$) occupied by 75 g ethane at S.T.P. ?

"Mass can neither be created nor destroyed" is the statement of