Which among the following is the popular method for manufacture of ammonia ?
- A.Ostwald's process
- B.Haber-Bosch process
- C.Electric furnace process
- D.Electrolysis process
Correct answer
Explanation
The correct answer is B, Haber-Bosch process. Almost all the world's ammonia is made by combining nitrogen and hydrogen directly in this process. In the Haber-Bosch process, nitrogen from the air and hydrogen, usually obtained from natural gas, are made to react in the ratio 1 to 3. The reaction is carried out at about 450 to 500 degrees Celsius and a pressure of around 200 atmospheres, with finely divided iron as the catalyst and molybdenum as a promoter. Fritz Haber worked out the reaction and Carl Bosch scaled it up for industry; both received Nobel Prizes. The ammonia is used mainly to make fertilisers such as urea. Option A is wrong because Ostwald's process makes nitric acid by oxidising ammonia, so it uses ammonia rather than producing it. Option C is wrong because the electric furnace process is used for products such as calcium carbide and phosphorus. Option D is wrong because electrolysis is used for sodium hydroxide, chlorine and metals such as aluminium. Exam tip: Haber gives ammonia, Ostwald gives nitric acid, Contact process gives sulphuric acid.
Practice Questions
View allWhich one of the following plant tissues has dead cells ?
- A.Epidermis
- B.Parenchyma
- C.Collenchyma
- D.Sclerenchyma
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Sclerenchyma cells are dead at maturity, with thick walls hardened by lignin. Sclerenchyma is the tissue that makes plants hard and stiff.
Read the full explanation →Imagine a current-carrying straight conductor with magnetic field of lines in anti-clockwise direction. Then the direction of current is determined by
- A.the Right-Hand Thumb rule and it would be in the downward direction.
- B.the Left-Hand Thumb rule and it would be in the downward direction.
- C.the Right-Hand Thumb rule and it would be in the upward direction.
- D.the Left-Hand Thumb rule and it would be in the upward direction.
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For a straight wire, the right-hand thumb rule links the current to the circular field lines around it. Hold the wire in the right hand with the thumb along the current; the curled fingers then show the direction of the magnetic field lines, which form concentric circles around the wire.
Read the full explanation →Which one of the following statements is true for sound waves propagating in air?
- A.Sound is an electromagnetic wave and transverse in nature
- B.Sound is a mechanical wave and longitudinal in nature
- C.Sound is a mechanical wave and transverse in nature
- D.Sound is an electromagnetic wave and longitudinal in nature
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Sound needs a material medium to travel, and in air its particles vibrate back and forth along the direction the wave moves.
Read the full explanation →Which one of the following is primarily responsible for conduction of current in a metal?
- A.Bound electrons
- B.Free electrons
- C.Both bound and free electrons
- D.Ions
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In a metal, the outer electrons of the atoms are not tied to any one atom and drift through the lattice when a voltage is applied, carrying the current.
Read the full explanation →Which one of the following statements is correct about the magnification of an optical microscope?
- A.Magnification increases with the increase in focal length of eyepiece
- B.Magnification increases with the increase in focal length of objective
- C.Magnification does not depend upon the focal length of eyepiece
- D.Magnification decreases with the increase in focal length of eyepiece
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A compound microscope magnifies more when both its lenses have short focal lengths. In a compound microscope the objective forms a real, enlarged image, and the eyepiece magnifies it further like a simple magnifier.
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