Photo AI
Tetrafluoroethene is made from chlorodifluoromethane in this reversible reaction - AQA - A-Level Chemistry - Question 2 - 2022 - Paper 2
Question 2
Tetrafluoroethene is made from chlorodifluoromethane in this reversible reaction. \[ 2CHCl_2(g) \rightleftharpoons C_2F_4(g) + 2HCl(g) \] \[ \Delta H = +128\, kJ\, ... show full transcript
Worked Solution & Example Answer:Tetrafluoroethene is made from chlorodifluoromethane in this reversible reaction - AQA - A-Level Chemistry - Question 2 - 2022 - Paper 2
Step 1
Calculate the amount, in moles, of C₂F₄ and of HCl in the equilibrium mixture.
Answer
Initial moles of CHCl₂F = 2.00 mol. At equilibrium, moles of CHCl₂F = 0.270 mol.
Change in moles of CHCl₂F = 2.00 mol - 0.270 mol = 1.73 mol.
From the balanced equation: [ 2CHCl_2F \rightarrow C_2F_4 + 2HCl ] 1 mole of C₂F₄ forms for every 2 moles of CHCl₂F that react, so:
[ \text{Moles of } C_2F_4 = \frac{1.73}{2} = 0.865 , \text{mol} ]
For HCl, 2 moles of HCl are produced for every 2 moles of CHCl₂F: [ \text{Moles of } HCl = 1.73 , \text{mol} ]
Step 2
Step 3
Step 4
State and explain the effect of using a higher temperature on the equilibrium yield of tetrafluoroethene.
Answer
Effect on yield: Yield would increase.
Explanation: Increasing the temperature shifts the equilibrium to favor the endothermic reaction, which is the forward reaction that produces tetrafluoroethene.
Step 5
Step 6