Home
Class 12
CHEMISTRY
Aluminothermy used for the spot welding ...

Aluminothermy used for the spot welding of large iron structures is based upon the fact that :

A

As compared to iron, aluminium has greater affinity for oxygen

B

As compared to aluminium, iron has greater affinity for oxygen

C

Reaction between aluminium and oxygen is endothermic

D

Reaction between iron oxide and aluminium is exothermic

Text Solution

AI Generated Solution

The correct Answer is:
To solve the question regarding the use of aluminothermy in spot welding of large iron structures, we will analyze the options provided and determine the correct answer based on the principles of aluminothermic reactions. ### Step-by-Step Solution: 1. **Understanding Aluminothermy**: - Aluminothermy is a process that involves the use of aluminum as a reducing agent to extract metals from their oxides at high temperatures. It is particularly useful in welding and metal extraction processes. 2. **Analyzing the Options**: - **Option 1**: "As compared to iron, aluminum has greater affinity for oxygen." - This statement is true. Aluminum is more reactive than iron and has a greater tendency to combine with oxygen. This property allows aluminum to act as a reducing agent in the reaction with iron oxide. - **Option 2**: "As compared to aluminum, iron has greater affinity for oxygen." - This statement is false. As established, aluminum has a greater affinity for oxygen than iron. - **Option 3**: "Reaction between aluminum and oxygen is endothermic." - This statement is also false. The reaction between aluminum and oxygen is exothermic, meaning it releases heat. - **Option 4**: "Reaction between iron oxide and aluminum is exothermic." - This statement is true. The reaction between iron oxide (Fe2O3) and aluminum is indeed exothermic, which means it generates a significant amount of heat, facilitating the welding process. 3. **Conclusion**: - Based on the analysis, the correct options that explain why aluminothermy is used for spot welding of large iron structures are: - **Option 1**: Aluminum has a greater affinity for oxygen than iron. - **Option 4**: The reaction between iron oxide and aluminum is exothermic. ### Final Answer: The correct statements regarding aluminothermy used for spot welding of large iron structures are: - Option 1: As compared to iron, aluminum has greater affinity for oxygen. - Option 4: Reaction between iron oxide and aluminum is exothermic. ---
Promotional Banner

Topper's Solved these Questions

  • METALLURGY

    VK JAISWAL ENGLISH|Exercise MATCH THE COLUMN|20 Videos

  • METALLURGY

    VK JAISWAL ENGLISH|Exercise ASSERTION-REASON TYPE QUESTIONS|29 Videos

  • METALLURGY

    VK JAISWAL ENGLISH|Exercise Level 3 (Passive 7)|8 Videos

  • ENVIRONMENTAL CHEMISTRY

    VK JAISWAL ENGLISH|Exercise ASSERTION-REASON TYPE QUESTIONS|14 Videos

  • p-BLOCK ELEMENTS

    VK JAISWAL ENGLISH|Exercise SUBJECTIVE PROBLEMS|35 Videos

Similar Questions

Explore conceptually related problems

Aluminothermy used for on the spot welding of large iron structures is based upon the fact that

The cyclotron is a device which is used to accelerate charged particles such as protons, deutrons, alpha particles, etc. to very high energy. The principle on which a cyclotron works is based on the fact that an electric field can accelerate a charged particle and a magnetic field can throw it into a circular orbit. A particle of charge +q experiences a force qE in an electric field E and this force is independent of velocity of the particle. The particle is accelerated in the direction of the magnetic field. On the other hand, a magnetic field at right angles to the direction of motion of the particle throws the particle in a circular orbit in which the particle revolves with a frequency that does not depend on its speed. A modest potential difference is used as a sources of electric field. If a charged particle is made to pass through this potential difference a number of times, it will acquire an enormous by large velocity and hence kinetic energy. The working of a cyclotron is based on the fact that

The cyclotron is a device which is used to accelerate charged particles such as protons, deutrons, alpha particles, etc. to very high energy. The principle on which a cyclotron works is based on the fact that an electric field can accelerate a charged particle and a magnetic field can throw it into a circular orbit. A particle of charge +q experiences a force qE in an electric field E and this force is independent of velocity of the particle. The particle is accelerated in the direction of the magnetic field. On the other hand, a magnetic field at right angles to the direction of motion of the particle throws the particle in a circular orbit in which the particle revolves with a frequency that does not depend on its speed. A modest potential difference is used as a sources of electric field. If a charged particle is made to pass through this potential difference a number of times, it will acquire an enormous by large velocity and hence kinetic energy. Which of the following cannot be accelerated in a cyclotron?

The cyclotron is a device which is used to accelerate charged particles such as protons, deutrons, alpha particles, etc. to very high energy. The principle on which a cyclotron works is based on the fact that an electric field can accelerate a charged particle and a magnetic field can throw it into a circular orbit. A particle of charge +q experiences a force qE in an electric field E and this force is independent of velocity of the particle. The particle is accelerated in the direction of the magnetic field. On the other hand, a magnetic field at right angles to the direction of motion of the particle throws the particle in a circular orbit in which the particle revolves with a frequency that does not depend on its speed. A modest potential difference is used as a sources of electric field. If a charged particle is made to pass through this potential difference a number of times, it will acquire an enormous by large velocity and hence kinetic energy. Cyclotron is not suitable for accelerating

Alkali metals oxide are obtained by combustion of the metals.Although Na normally gives Na_2O_2 ,it will take up further oxygen at elevated pressure and temperature to form NaO_2 .The per and superoxides of the heavier alkalies can also be prepared by passing stoichiometric amounts of oxygen into their solution in liquid ammonia. The different alkali metal oxides can be distinguished by reaction with water.The superoxides reacts with CO_2 and give oxygen gas.The stability of per and superoxides is based upon that larger cation can stablise larger anion, due to larger lattice energy. Alkali metals dissolve in liquid ammonia.Dilute solutions are dark blue in colour but as the concentration increases above 3M, the colour changes to copper bronze and the solution acquires the metallic lusture due to the formation of metal ions clusters.The solutions of alkali metals in liquid ammonia are good conductors of electricity due to the presence of ammoniated cations and ammoniated electrons.However, the conductivity decreases as the concentrations increases, since ammoniated electrons and ammoniated cation associate. KO_2 is used in oxygen cylinders in space and submarines because it :

Account for the following facts: (a) The reduction of a metal oxide is easier if the metal formed is in the liquid state at the temperature of reduction. (b) Limestone is used in the manufacture of pig iron from haematite. (c) Pine oil is used in the froth flotation process used to concentrate sulphide ores.

read the following statements: statement A: modern taxonomic studies are based on external and internal structure of organisms along with cell structure, development process an ecological information of organisms. statement B: neo-systematics is best upon morphological characters only.

Internal micrometer is a measuring intrument used to measure internal diameter (ID) of a large cylinder bore with high accuracy. Construction is shown in figure. There is one fixed rod B (to the right in figure) and one moved rod A (to the left in figure). It is based on the particle of advancement of a screw when it is rotated in a nut with internal threads. Main scale reading can be directly seen on the hub which is fixed with respect to rod B. When the cap is rotated rod A moves in or cut depending on direction of rotation. The circular scale reading is seen by checking which division of circular scale coincide with the references line This is to be multiplied by LC to get circular scale reading. Least count = value of 1 circular scale division = ("pitch")/("number of division on circular scale") Length of rod A is chosen to match the ID(PQ) to be measured. Zero error is checked by taking reading between standard blocks fixed at normal value of ID to be measured. Zero error is positive if cap end is one the right of the main scale and negative it is on the left side. During zero setting of the above instrument, the end of the cap is on left side of the zero of main scale (i.e. zero of main scale is not visible) and 41^(th) division of circular scale coincides with the reference line, the zero error is -

Internal micrometer is a measuring intrument used to measure internal diameter (ID) of a large cylinder bore with high accuracy. Construction is shown in figure. There is one fixed rod B (to the right in figure) and one moved rod A (to the left in figure). It is based on the particle of advancement of a screw when it is rotated in a nut with internal threads. Main scale reading can be directly seen on the hub which is fixed with respect to rod B. When the cap is rotated rod A moves in or cut depending on direction of rotation. The circular scale reading is seen by checking which division of circular scale coincide with the references line This is to be multiplied by LC to get circular scale reading. Least count = value of 1 circular scale division = ("pitch")/("number of division on circular scale") Length of rod A is chosen to match the ID(PQ) to be measured. Zero error is checked by taking reading between standard blocks fixed at normal value of ID to be measured. Zero error is positive if cap end is one the right of the main scale and negative it is on the left side. In the above instrument, while measuring an internal diameter. ID is set of 321 mm with no zero error. It cap end is after 7^(th) division adn 17^(th) division of main scale coincides with the reference line, the ID is -

VK JAISWAL ENGLISH-METALLURGY-One OR MORE ANSWERS IS/ ARE CORRECT
  1. Of the following reduction processes, correct processes are :

    Text Solution

    |

  2. In the extraction of aluminium metal, one of the process is summarised...

    Text Solution

    |

  3. During the production of iron and steel.

    Text Solution

    |

  4. The smelting of iron in a blast furnace involves the following process...

    Text Solution

    |

  5. For which of the following metals can be extracted by aluminothermic p...

    Text Solution

    |

  6. For which of the following metal, the carbon reduction cannot be used ...

    Text Solution

    |

  7. The advantage(s) of using carbon to reduce a number of oxides and othe...

    Text Solution

    |

  8. The disadvantage of carbon reduction method are :

    Text Solution

    |

  9. Which of the following metal (s) is /are commercially extracted by sel...

    Text Solution

    |

  10. Which of the following is / are correctly matched ?

    Text Solution

    |

  11. The funciton of adding cryolite in the electrolytic reduction of alumi...

    Text Solution

    |

  12. Which of the following reduction reactions are actually employed in co...

    Text Solution

    |

  13. The main reaction occuring in blast furnance during extraction of iron...

    Text Solution

    |

  14. Which of the following are true for electrolytic extraction of alumini...

    Text Solution

    |

  15. Select correct statement regarding silver extraction process .

    Text Solution

    |

  16. Aluminothermy used for the spot welding of large iron structures is ba...

    Text Solution

    |

  17. Highly electropositive metals can not be extracted by carbon reduction...

    Text Solution

    |

  18. Which of the following reaction in the blast furnace is / are endother...

    Text Solution

    |

  19. The funace lining in steel manufacture consists of :

    Text Solution

    |

  20. Pick up the correct statement(s) :

    Text Solution

    |