Question

calculate the number of moles present in 9g of ethane...

help...plz...

Answer 1

Mass of the ethane =9g
Chemical formula of ethane=C2H6
Molar mass of the ethane=12×2+1×6=24+6=30

No.of moles=Mass/Molar mass
No.of moles of the ethane =9/10=3/10=0.3

Hence, the no.of the moles of 9g of the ethane is 0.3moles.

Answer 2

Given:

The mass of ethane = 9g

To Find:

The number of moles present in 9g of ethane

Solution:

The number of moles of a substance in a given sample = m /M     -(1)

Here, m = The given mass of the element or compound

M = The gram molar mass of the given element or compound

Ethane is an organic compound with the formula CH₃CH₃.

Its molecular mass = 2 X Molecular mass of Carbon + 6 X Molecular mass of Hydrogen

We know that the molecular masses of Carbon and Hydrogen are 12g and 1g respectively

Substituting,

Molecular mass of ethane = 2 X 12 + 6 X 1

= 24 + 6 = 30g

Substituting in equation 1,

The number of moles = 9 / 30 = 0.3

Hence, the number of moles present in 9g of ethane is 0.3.