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# Equilibria

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This question is about the Haber process:
N2(g) + 3H2(g) ⇌ 2NH3(g)
The forward reaction is exothermic. 120 moles of hydrogen gas are mixed with 40.0 moles of nitrogen gas and pressurised. The mixture of gases is passed over an iron catalyst at 450 °C until the mixture reaches equilibrium. 20.0% of the reactants are converted to ammonia. The total volume of the mixture is 1.00 dm3.

a How many moles of nitrogen and of hydrogen remain at equilibrium? [2]
b How many moles of ammonia are formed? [1]

My working
20/100 × 160 = 32
32 moles of ammonia are formed
N2 H2 NH3
Initial moles 40 120 0
Change -x -3x +2x
At equilbrium 40-x 120-3x 32
So x is 16
Im getting H2 72 moles and N2 24

The RIGHT ANSWERS ARE H2 96
N2 32

WHATS WRONG WITH MY WORKING??
2. (Original post by Insia786)

This question is about the Haber process:
N2(g) + 3H2(g) ⇌ 2NH3(g)
The forward reaction is exothermic. 120 moles of hydrogen gas are mixed with 40.0 moles of nitrogen gas and pressurised. The mixture of gases is passed over an iron catalyst at 450 °C until the mixture reaches equilibrium. 20.0% of the reactants are converted to ammonia. The total volume of the mixture is 1.00 dm3.

a How many moles of nitrogen and of hydrogen remain at equilibrium? [2]
b How many moles of ammonia are formed? [1]

My working
20/100 × 160 = 32
32 moles of ammonia are formed
N2 H2 NH3
Initial moles 40 120 0
Change -x -3x +2x
At equilbrium 40-x 120-3x 32
So x is 16
Im getting H2 72 moles and N2 24

The RIGHT ANSWERS ARE H2 96
N2 32

WHATS WRONG WITH MY WORKING??
Find the 20% for the nitrogen and the hydrogen moles separately, this would give you the correct answer.
3. Whats wrong with my ice tablee?
Why isnt the answer coming through that method?
4. (Original post by Insia786)
Whats wrong with my ice tablee?
Why isnt the answer coming through that method?
No idea tbh but why did you not just take the 32 divide it by 4 as 1 N and 3 H and subtract that number (8) from the nitrogen moles and from the hydrogen moles.
5. Why 4?
It should be divided by 2 since we have 2 moles of ammonia
6. (Original post by Insia786)
Why 4?
It should be divided by 2 since we have 2 moles of ammonia
4 atoms in one mole, not 4 as the number of moles.
7. 20% of 120 mol of H2 (24 mol) is used up, 96 mol remains.
20% of 40 mol of N2 (8 mol) is used up, 32 mol remains.

The balanced equation shows that 1 mol of N2 (and 3 mol of H2) forms 2 mol of NH3.
Therefore the 8 mol of N2 will form 16 mol of NH3.

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Updated: April 27, 2016
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