Butane mol a sample of an alcohol is tested and found to contain 52% carbon, 35% oxygen, and 13% hydrogen by mass.
tests indicate that the molecular weight of the molecule is between 30 and 80.
what is the molecular formula of the alcohol?

Explanation:

For a compound as:

Let say your sample weighs 100 g, then you have

52 g of C

35 g of O

13 g of H

Now you need to calculate the  moles in the sample:

moles of C = 52 / 12 = 4.3333

moles of O = 35 / 16 = 2.1875

moles of H = 13 / 1 = 13

Now you divide the moles by the least to have a proportion (2.1875):

moles of C = 4.3333 / 2.1875 = 2

moles of O = 2.1875 / 2.1875 = 1

moles of H = 13 / 2.1875 = 6

So the molecule proportion of atoms is C:H:O = 2:6:1

Now to find x you have to calculate the MM:

MM = 12 * 2x + 1 * 6x + 16 * x = 46x

For x = 1 => MM = 46(1) = 46

For x = 2 => MM = 46(2) = 92

Since the MM is between 30 and 80, x = 1

a gas, having a molecular weight of 13 kg/kmol and a kinematic viscosity of 0.25 cm2/s, flows through a pipe 0.25 m internal diameter and 5 km long at the rate of 0.4 m3/s and is delivered at atmospheric pressure.