Chemical Technology And Plant Design

Step 1: Understanding secondary nutrients.
In fertilizers, secondary nutrients are nutrients that are essential for plant growth but required in smaller amounts than primary nutrients (nitrogen, phosphorus, potassium). Calcium, magnesium, and sulfur are considered secondary nutrients.

Step 2: Explanation of options.
- (D) Calcium, magnesium, and sulfur are indeed secondary nutrients in fertilizers. - (A), (B), and (C) These options refer to trace elements or micronutrients, not secondary nutrients.

Final Answer:

Step 1: Understanding feedstock in the petrochemical industry.
Naphtha is a petroleum fraction with a boiling range between 20°C and 200°C, making it suitable as a feedstock for various petrochemical processes, including cracking.

Step 2: Explanation of options.
- (C) Naphtha is the correct feedstock with the given boiling range. - (A) Kerosene has a higher boiling point and is not typically used in cracking. - (B) Gas oil is a heavier fraction than naphtha. - (D) LPG has a boiling point below 20°C.

Final Answer:

Step 1: Understanding the oxidation process.
In the industrial production of nitric acid, the oxidation of ammonia takes place in the presence of a platinum-rhodium catalyst. The ammonia is mixed with air to initiate the reaction. The concentration of ammonia in the feed gas entering the converter is typically very low, generally between 1 and 2%, to avoid excessive heat generation and ensure a controlled reaction rate.

Step 2: Explanation of other options.
- (B) 10 to 12% ammonia is too high and would lead to a highly exothermic reaction, which is not typical in the first step. - (C) and (D) 40 to 50% or 70 to 80% ammonia would be far too concentrated for the initial oxidation reaction.

Final Answer:

Step 1: Understanding bracket supports.
Bracket supports are designed to support vessels that are heavy or require additional stability, making them suitable for thick-walled vertical vessels. These vessels are typically more rigid and require robust support systems.

Step 2: Explanation of options.
- (A) Bracket supports are ideal for thick-walled vertical vessels. - (B) Horizontal vessels are typically supported by different types of supports. - (C) Thin spherical vessels do not require bracket supports. - (D) Thin walled vertical vessels usually require different support structures.

Final Answer:

Step 1: Understanding break-even point.
The break-even point is the point where total revenue equals total cost, resulting in zero profit. It depends on fixed costs, variable costs, and unit contribution (the amount contributed per unit to cover fixed costs).

Step 2: Explanation of options.
- (C) If the unit contribution decreases (i.e., the profit per unit decreases), the break-even point increases because more units need to be sold to cover fixed costs. - (A) A decrease in fixed cost would decrease the break-even point, not increase it. - (B) A decrease in variable cost for a given price would reduce the break-even point, not increase it. - (D) A decrease in manufacturing cost would reduce the break-even point.

Final Answer:

Step 1: Understanding cumulative cash flow.
The cumulative cash flow represents the net cash inflows and outflows over the life of the project. The point where the cumulative cash flow is zero is known as the **break-even point**.

Step 2: Explanation of other options.
- (A) **End of the project life**: At the end of the project life, the cash flow would typically be zero if all costs and revenues are accounted for. - (C) **Start-up**: This is the beginning phase, so the cumulative cash flow is usually negative due to initial investments. - (D) **End of the design stage**: At this stage, the project is still in the planning phase, so the cumulative cash flow is likely negative.

Final Answer:

Step 1: Understanding the formula for effective interest rate.
When interest is compounded monthly, the effective interest rate can be calculated using the formula: Where: - is the effective interest rate, - is the nominal interest rate, - is the number of compounding periods (monthly, so ).

Step 2: Apply the formula.
If the nominal interest rate is 24%, then:

Final Answer:

Step 1: Formula for payback period.
The payback period is calculated by:

Step 2: Calculate the annual return after tax.
The expected annual return is ₹50000. With corporate tax at 30%, the net return after tax is:

Step 3: Calculate the payback period.
Now, the payback period can be calculated as: Thus, the correct answer is 3 years.

Final Answer: