Correct Answer:
(C)
Hydrogen
Transition metals are used directly as catalysts in the anti–pollution catalytic converters in car exhausts. For example, expensive transition metals such as Platinum and rhodium are used in the catalytic converters in car exhausts to reduce the emission of carbon monoxide and nitrogen monoxide, which are converted to the non–polluting gases nitrogen and carbon dioxide.
2NO (g) + 2CO(g) —> N2 (g) + 2CO2 (g)
Ques:
12
Which of the following chemical fertilizers is relatively more soluble in water at 20oC?
Correct Answer:
(B)
Urea
Urea is an organic compound that is only stable in an acidic environment. It is named after the Greek word 'Oura' meaning urine. Urea is very easily soluble in water as compared to other fertilizers.
Ques:
13
With reference to chemical fertilizers in India, consider the following statements :
At present, the retail price of chemical fertilizers is market-driven and not administered by the Government.
Ammonia, which is an input of urea, is produced from natural gas.
Sulphur, which is a raw material for phosphoric acid fertilizer, is a by-product of oil refineries.
Which of the statements given above is/are correct?
Correct Answer:
(B)
2 and 3 only
Statement 1 is incorrect as urea is a main chemical fertilizer and MRP of urea is statutorily fixed by the Government. Government has implemented the Nutrient Based Subsidy (NBS) policy w.e.f. 1.4.2010 for Phosphatic and Potassic (P&K) fertilizers. Under the policy, MRP of P&K fertilizers has been left open and fertilizer manufacturers/marketers are allowed to fix the MRP at reasonable rates as per market dynamics, while the Government announces nutrient based subsidy for them. Ammonia is used to produce various nitrogenous fertilizers, including urea. For the industrial purposes, ammonia is manufactured by Haber's process, for which hydrogen is obtained from natural gas. Natural gas contains methane (CH4) which is used to produce hydrogen with thermal processes, such as steam-methane reformation and partial oxidation. Hence, statement 2 is correct. Statement 3 is also correct as in India the domestic production of elemental sulphur is limited to by - product recoveries from petroleum refineries which is a raw material for phosphoric acid fertilizers.
Ques:
14
What can be the impact of the excessive/ inappropriate use of nitrogenous fertilizers in agriculture?
The proliferation of nitrogen-fixing microorganisms in soil can occur.
The increase in the acidity of soil can take place.
Leaching of nitrate to the groundwater can occur.
Select the correct answer using the code given below.
Correct Answer:
(C)
2 and 3 only
The excess use of nitrogenous fertilizers in agriculture can affect environment in various manners for example, increment of acidity in the soil, leaching of ground water, eutrophication etc.