Sulfuric acid is manufactured by the Contact process - CIE - A-Level Chemistry - Question 1 - 2018 - Paper 1
Question 1
Sulfuric acid is manufactured by the Contact process.
One stage in this process is the conversion of sulfur dioxide into sulfur trioxide in the presence of a hetero... show full transcript
Worked Solution & Example Answer:Sulfuric acid is manufactured by the Contact process - CIE - A-Level Chemistry - Question 1 - 2018 - Paper 1
Step 1
State the effect of a catalyst on a reaction. Explain how a catalyst causes this effect.
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Answer
A catalyst speeds up a reaction by providing an alternative pathway with a lower activation energy (Ea). This allows more reactant molecules to collide successfully, resulting in an increased reaction rate.
Step 2
State the meaning of the term heterogeneous as applied to catalysts.
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Answer
A heterogeneous catalyst is in a different phase (state) from the reactants.
Step 3
Use the data to calculate a value for the S=O bond energy in SO3.
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Answer
To find the S=O bond energy in SO3, we use the formula:
Complete the table by stating which letter represents the energy change described.
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Answer
A = Energy change for the production of SO3
B = Activation energy for the production of SO2 in the absence of a catalyst
D = Activation energy for the first step in the decomposition of SO3 in the presence of a catalyst
Step 5
State and explain the effect of increasing temperature on the rate of production of SO3.
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Answer
Increasing the temperature increases the rate of production of SO3. This happens because higher temperatures increase the kinetic energy of the molecules, leading to more frequent and effective collisions per unit time, thus raising the number of successful collisions.
Step 6
State and explain the effect of increasing temperature on the yield of SO3.
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Answer
Increasing temperature will decrease the yield of SO3, as the formation of SO3 is exothermic, and shifting equilibrium will favor the endothermic direction (reverse reaction) to counteract the temperature rise.
Step 7
Suggest an equation for the reaction of oleum, H2S2O7, with water to form sulfuric acid.
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H2S2O7 + H2O → 2H2SO4
Step 8
Complete the ‘dot-and-cross’ diagram to show the bonding in a molecule of SO2.
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Answer
The dot-and-cross diagram for SO2 should depict the sharing of electrons between sulfur (S) and oxygen (O) atoms, showing outer electrons only.
Step 9
State the meaning of the term strong Brønsted-Lowry acid.
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A strong Brønsted-Lowry acid is a substance that donates protons (H+) easily in a reaction.
Step 10
Write an equation to show the acidic behaviour of sulfuric acid with water. Include state symbols.
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