Question

A sample of ethane (C2H6) gas has same mass as 1.5x 10-9 molecules of methane
(CH4). How many ethane molecules do the sample of gas has?

​

Answer 1

Answer:

Explanation:

Mass of 1 molecule of CH  

4

​  

=  

N  

A

​  

 

16

​  

 g

Mass of 1.5×10  

20

 molecules of methane =  

N  

A

​  

 

1.5×10  

20

×16

​  

g

Mass of x molecules of C  

2

​  

H  

6

​  

 is =  

N  

A

​  

 

1.5×10  

20

×16

​  

g

We know that mass of 1 molecule of C  

2

​  

H  

6

​  

=  

N  

A

​  

 

30

​  

g

∴ Number of molecules of ethane (x) =  

N  

A

​  

 

1.5×10  

20

×16

​  

×  

30

N  

A

​  

 

​  

=0.8×10  

20