Jawabanmu

2014-06-08T21:31:14+07:00
M = 2,2 gr
N = 3x10^22

n = N / bil avogadro
= 3x10^22 / 6x10^23
= 0,05mol

mr = m / n
= 2,2gr / 0,05mol 
= 44
jadi rumus molekulnya C3H8