Mole Concept

  • #1
168
1

Homework Statement


30 litres of N2 and 30 litres of H2 are taken in Habers process with 50% yield.What is the final composition of the compunds in litres?

Homework Equations


N2+3H2->2NH3

The Attempt at a Solution


N2 + 3H2-> 2NH3
intial: 30 30 0
final: 30 - x/2 30-(3x)/2 (2x)/2

so,
30 - x/2 + 30-(3x)/2 = (2x)/2

this gives x=20
N2=20L
H2=0L
NH3=20L

Am i right?
 

Answers and Replies

  • #2
35,265
11,525
so,
30 - x/2 + 30-(3x)/2 = (2x)/2
Why do you expect these two to be equal?

How is the yield defined? Using all hydrogen with just 50% yield is odd.
 
  • #3
168
1
Why do you expect these two to be equal?

Howis the yield defined? Using all hydrogen with just 50% yield is odd.
litres are conserved
50 percent yield means half of theoretical value of NH3
 
  • #4
Borek
Mentor
28,635
3,106
litres are conserved
2 L of hydrogen plus 1 L of oxygen produce 2 L of gaseous water, 2+1 yields 2, what is conserved here?

50 percent yield means half of theoretical value of NH3
If only 50% of ammonia was produced, was all the limiting reagent consumed?
 
  • #5
168
1
2 L of hydrogen plus 1 L of oxygen produce 2 L of gaseous water, 2+1 yields 2, what is conserved here?



If only 50% of ammonia was produced, was all the limiting reagent consumed?
Ok i understand the limiting concept now.

NH3 produced=2/3 x 30 =20 L

H2 left= 0 L

N2 left= 30- (1/2 x 20) =20 L
 
  • #6
Borek
Mentor
28,635
3,106
So which one is the limiting reagent here? And how much was left if only 50% reacted?
 
  • Like
Likes Suyash Singh
  • #7
168
1
So which one is the limiting reagent here? And how much was left if only 50% reacted?
H2 the limiting reagent

all the elements react only 50 %?
 
  • #8
Borek
Mentor
28,635
3,106
H2 the limiting reagent
Right.

all the elements react only 50 %?
Stop guessing, use stoichiometry to calculate.
 
  • #9
35,265
11,525
50 percent yield means half of theoretical value of NH3
But you got all of the maximum yield of NH3: You used up all hydrogen.
Based on that you can figure out how much NH3 is produced if you use only half of it.
 
  • #10
168
1
NH3 produced = 50/100 x (2/3 x 30) = 10 L
H2 left
= 30 - (3/2 x 10) = 15 L
N2 left
= 30 - (1/2 x 10)= 25 L
 
  • #11
35,265
11,525
That looks good.
 
  • Like
Likes Suyash Singh

Related Threads on Mole Concept

  • Last Post
Replies
2
Views
861
  • Last Post
Replies
6
Views
2K
  • Last Post
Replies
3
Views
583
  • Last Post
Replies
5
Views
2K
  • Last Post
Replies
4
Views
2K
  • Last Post
Replies
2
Views
4K
  • Last Post
Replies
8
Views
4K
Replies
2
Views
6K
Replies
6
Views
34K
  • Last Post
Replies
3
Views
13K
Top