DThe process involves a non-reversible reaction.[1]
The Haber process is reversible: ammonia breaks down into nitrogen and hydrogen as it forms.
C1 only[1]
A high pressure increases both. A high temperature speeds up the reaction but lowers the yield, and a catalyst speeds up the reaction without changing the yield.
D2000 dm3 of nitrogen and 6000 dm3 of hydrogen[1]
Volume of ammonia if the reaction were complete = 600 × 10015 = 4000 dm3.
N2 : H2 : NH3 = 1 : 3 : 2, so 2000 dm3 of nitrogen and 6000 dm3 of hydrogen are needed.
C45 cm3[1]
15 cm3 of nitrogen reacts with 45 cm3 of hydrogen to form 30 cm3 of ammonia. 15 cm3 of hydrogen is left over, so the total is 30 + 15 = 45 cm3.
DThe damp red litmus paper turns blue first, and both papers end red.[1]
Ammonia (Mr 17) diffuses faster than hydrogen chloride (Mr 36.5), so it reaches the papers first and turns the red paper blue. Hydrogen chloride arrives later and turns both papers red.
By the cracking of crude oil fractions (hydrocarbons). [1]
Nitrogen has the electronic structure 2.5, with 5 valence electrons. [1]
It needs three more electrons to fill its valence shell, so it shares one electron with each of three hydrogen atoms. [1]
As the temperature increases, the yield decreases. [1]
It increases the yield of ammonia. [1]
A higher pressure is a safety risk (risk of explosion) or the plant is too expensive to build to withstand it. [1]
They are recycled: sent over the catalyst again. [1]
The yield of ammonia decreases (from 38.5% to 14.1%) as the temperature increases (from 350 °C to 550 °C). [1]
From 100 to 300 atm the yield increases by 30.1 − 14.5 = 15.6%, and from 550 °C to 350 °C it increases by 38.5 − 14.1 = 24.4%. [1]
This is 0.078% for every 1 atm and 0.122% for every 1 °C. [1]
No, I do not agree: decreasing the temperature produces a larger increase in the yield. [1]
It contributes to greenhouse gas emissions, leading to global warming. [1]
N2(g) + 3H2(g) ⇌ 2NH3(g) [1]
From the equation, 1 volume of nitrogen reacts with 3 volumes of hydrogen. [1]
About 450 °C, about 250 atm and a finely divided iron catalyst (all three for the mark). [1]
Upward delivery [1]
because ammonia is less dense than air. [1]
NH3 : NO = 1 : 1 by volume, so the theoretical volume of NO = 440 dm3 [1]
Volume collected = 40100 × 440 = 176 dm3 [1]