Question

how many molecules will be in 275 grams of c2h6

Answer 1

Calculate molar mass of C2H6 = 30 g mole

Number of moles is then
275 g/30 g mol^-1 = 9.2 mole

1 mole contains 6.02 x 10^23 molecules (Avogadro's number)

So number of molecules =
6.02 x 10^23 molecules mole^-1 x 9.2 mole =

Answer 2

muja numarical sikhna hai