This question is about methanol. 1. Methanol is broken down in the body during digestion. What type of substance acts as a catalyst in this process? Tick one box. Amino acid Enzyme Ester Nucleotide 2. In industry, methanol is produced by reacting carbon monoxide with hydrogen. The equation for the reaction is: CO(g) + 2H2(g) ⇌ CH3OH(g) How many moles of carbon monoxide react completely with 4.0 x 10³ moles of hydrogen? Tick one box. 1.0 x 10³ moles 2.0 x 10³ moles 4.0 x 10³ moles 8.0 x 10³ moles 3. The reaction is carried out at a temperature of 250 °C and a pressure of 100 atmospheres. The forward reaction is exothermic. Explain what happens to the yield of methanol if a temperature higher than 250 °C is used. 4. A pressure of 100 atmospheres is used instead of atmospheric pressure. The higher pressure gives a greater yield of methanol and an increased rate of reaction. Explain why. 5. A catalyst is used in the reaction to produce methanol from carbon monoxide and hydrogen. Explain how a catalyst increases the rate of a reaction. 6. Suggest why a catalyst is used in this industrial process. Do not give answers in terms of increasing the rate of reaction. 7. Suggest the effect of using the catalyst on the equilibrium yield of methanol.

GCSE AQA Chemistry Exothermic & Endothermic Reactions: This question is about methanol.

This question is about methanol - AQA - GCSE Chemistry - Question 9 - 2018 - Paper 2

Question 9

This question is about methanol. 1. Methanol is broken down in the body during digestion. What type of substance acts as a catalyst in this process? Tick one box. ... show full transcript

Worked Solution & Example Answer:This question is about methanol - AQA - GCSE Chemistry - Question 9 - 2018 - Paper 2

Step 1

Methanol is broken down in the body during digestion. What type of substance acts as a catalyst in this process?

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Answer

The substance that acts as a catalyst during digestion is an enzyme. Enzymes are biological catalysts that facilitate biochemical reactions in the body.

Step 2

How many moles of carbon monoxide react completely with 4.0 x 10³ moles of hydrogen?

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Answer

In the balanced reaction, the mole ratio of carbon monoxide (CO) to hydrogen (H₂) is 1:2. Thus, to find the moles of CO needed for 4.0 x 10³ moles of H₂:

$ext{Moles of CO} = rac{1}{2} imes 4.0 imes 10^3 = 2.0 imes 10^3 ext{ moles}$ The correct answer is 2.0 x 10³ moles.

Step 3

Explain what happens to the yield of methanol if a temperature higher than 250 °C is used.

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Answer

If the temperature is increased above 250 °C, the yield of methanol decreases. This is because the forward reaction is exothermic, and according to Le Chatelier's Principle, raising the temperature shifts the equilibrium position towards the endothermic reaction, which is to the left. Therefore, less methanol is produced.

Step 4

The higher pressure gives a greater yield of methanol and an increased rate of reaction. Explain why.

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Answer

Using a higher pressure reduces the volume of the gas mixture, leading to a greater number of collisions between reactant particles. Since there are fewer gas moles on the product side (1 mole of CH₃OH compared to 3 moles of reactants), increasing the pressure shifts the equilibrium position towards the right, resulting in a higher yield of methanol. Additionally, increased pressure results in more collisions per unit time, enhancing the reaction rate.

Step 5

Explain how a catalyst increases the rate of a reaction.

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Answer

A catalyst increases the rate of reaction by providing an alternative reaction pathway with a lower activation energy. This allows more reactant molecules to collide with enough energy to react, thus speeding up the overall reaction without being consumed in the process.

Step 6

Suggest why a catalyst is used in this industrial process.

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Answer

A catalyst is used in this industrial process to reduce the energy requirements for the reaction. This leads to lower operational costs and makes the process more efficient without focusing on reaction rates.

Step 7

Suggest the effect of using the catalyst on the equilibrium yield of methanol.

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Answer

Using a catalyst has no effect on the equilibrium yield of methanol itself. It only increases the rate at which equilibrium is achieved, allowing the system to reach the equilibrium state faster.

This question is about methanol - AQA - GCSE Chemistry - Question 9 - 2018 - Paper 2

Worked Solution & Example Answer:This question is about methanol - AQA - GCSE Chemistry - Question 9 - 2018 - Paper 2

Methanol is broken down in the body during digestion. What type of substance acts as a catalyst in this process?

How many moles of carbon monoxide react completely with 4.0 x 10³ moles of hydrogen?

Explain what happens to the yield of methanol if a temperature higher than 250 °C is used.

The higher pressure gives a greater yield of methanol and an increased rate of reaction. Explain why.

Explain how a catalyst increases the rate of a reaction.

Suggest why a catalyst is used in this industrial process.

Suggest the effect of using the catalyst on the equilibrium yield of methanol.

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