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At temperatures above 100°C, hydrogen and carbon monoxide react to form methanol gas in this reversible reaction - HSC - SSCE Chemistry - Question 31 - 2015 - Paper 1
Question 31
At temperatures above 100°C, hydrogen and carbon monoxide react to form methanol gas in this reversible reaction. $$ 2H_2(g) + CO(g) \rightleftharpoons CH_3OH(g) $$... show full transcript
Worked Solution & Example Answer:At temperatures above 100°C, hydrogen and carbon monoxide react to form methanol gas in this reversible reaction - HSC - SSCE Chemistry - Question 31 - 2015 - Paper 1
Step 1
Calculate the equilibrium constant for this reaction.
Answer
At equilibrium, we have:
- Moles of : 0.36 mol
- Moles of : 0.99 mol (initially 1.00 mol - 0.01 mol used)
- Moles of : 2.32 mol (initially 2.50 mol + 0.18 mol formed)
First, calculate the concentrations at the new volume of 2.00 L:
The equilibrium constant (K) can be calculated using the formula:
Step 2
Explain the chemistry related to the cleaning properties of the product of saponification.
Answer
The product of saponification is soap, which acts as an emulsifying agent due to its unique molecular structure.
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Molecular Structure: Soap molecules have a hydrophobic (water-repelling) tail and a hydrophilic (water-attracting) head. This allows them to interact with both water and oil.
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Cleaning Mechanism: When soap is mixed with water and applied to a greasy surface, the hydrophobic tails of soap molecules attach to grease or oil, while the hydrophilic heads remain in contact with water. This interaction helps to break down and lift the grease off surfaces, allowing it to be washed away with water.
Thus, the ability of soap to make oil and water mix allows it to carry away dirt and grease, making it effective for cleaning purposes.
Step 3
Compare the membrane cell method with ONE other method used in the industrial production of sodium hydroxide in terms of technical and environmental issues.
Answer
The membrane cell method and the diaphragm cell method are two common techniques for producing sodium hydroxide ( ext{NaOH}).
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Membrane Cell Method:
- Technical Issues: This method is efficient, but the membranes can be expensive and require careful management to prevent degradation over time.
- Environmental Issues: It minimizes the release of chlorine gas into the environment and utilizes a process that is less likely to lead to pollution compared to other methods.
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Diaphragm Cell Method:
- Technical Issues: Involves a porous diaphragm that allows the passage of ions while preventing the mixing of chlorine and sodium hydroxide, but it is less efficient than the membrane method.
- Environmental Issues: This method can lead to the contamination of products and the production of less pure sodium hydroxide. The disposal of spent brine poses an environmental challenge as well.