ANS:C - produces lower purity acid.

In the manufacture of orthophosphoric acid (H3PO4), the strong sulfuric acid (H2SO4) leaching wet process, as compared to the electric furnace process:

1. Uses lower grade phosphate rock: The strong sulfuric acid leaching wet process is capable of efficiently extracting phosphoric acid from lower grade phosphate rock compared to the electric furnace process. This is because the wet process relies on the chemical reaction between sulfuric acid and phosphate rock to dissolve the phosphorus, allowing for the extraction of phosphoric acid.
2. Requires lower capital investment in the plant: The strong sulfuric acid leaching wet process typically requires lower capital investment in plant infrastructure compared to the electric furnace process. This is because the wet process involves simpler equipment and fewer steps compared to the electric furnace process, which may require more complex and specialized equipment for high-temperature reactions.
3. Produces lower purity acid: While the strong sulfuric acid leaching wet process is efficient for extracting phosphoric acid from phosphate rock, it may produce lower purity orthophosphoric acid compared to the electric furnace process. This is because impurities from the phosphate rock and sulfuric acid may carry over into the final product, requiring additional purification steps to achieve the desired purity.
4. Is very costly: The strong sulfuric acid leaching wet process may be costly in terms of operating expenses, particularly due to the high consumption of sulfuric acid and energy required for the process. Additionally, the need for additional purification steps to obtain higher purity acid may contribute to the overall cost of production.

Overall, while the strong sulfuric acid leaching wet process offers advantages such as the ability to use lower grade phosphate rock and lower initial capital investment, it may also have drawbacks such as lower purity of the final product and potentially higher operating costs. The choice between the wet process and the electric furnace process depends on factors such as the availability of raw materials, desired product purity, and economic considerations.