Stoichiometry

251. Pure oxide refractories are generally monocrystalline in nature and are self bonded _________ bricks are generally used as moderator in nuclear reactors.

  1. Beryllia
  2. Carborundum
  3. Corundum
  4. Thoria

Correct answer: (A)
Beryllia

252. Pure oxygen is mixed with air to produce an enriched air containing 50 volume % of oxygen. The ratio of moles of air to oxygen used is

  1. 1.72
  2. 0.58
  3. 0.5
  4. 0.2

Correct answer: (B)
0.58

253. Quartz is

  1. Stable form of silica upto 870°C
  2. Converted to Tridymite on firing between 870 to 1470°C
  3. Transformed to Cristobalite on heating above 1470°C
  4. All (A), (B) and (C)

Correct answer: (D)
All (A), (B) and (C)

254. Raoult's law is not applicable to the

  1. Solutes which dissociate or associate in the particular solution
  2. Concentrated solutions
  3. Both (B) & (C)
  4. Solutions containing non-volatile solute

Correct answer: (C)
Both (B) & (C)

255. Raoult's law is obeyed by a _________ solution.

  1. Saturated
  2. Molar
  3. Normal
  4. None of these

Correct answer: (D)
None of these

256. Raoult's law states that 'the equilibrium vapor pressure that is exerted by a component in a solution is proportional to the mole fraction of that component'. This generalisation is based on the assumption that the

  1. Sizes of the component molecules are approximately equal
  2. Attractive forces between like and unlike molecules are approximately equal
  3. Component molecules are non-polar and no chemical combination or molecular association between unlike molecules takes place in the formation of the solution
  4. All (A), (B) & (C)

Correct answer: (D)
All (A), (B) & (C)

257. Real gases approach ideal behaviour at

  1. High pressure & high temperature
  2. Low pressure & high temperature
  3. High pressure & low temperature
  4. Low pressure & low temperature

Correct answer: (B)
Low pressure & high temperature

258. Recycling in a chemical process facilitates

  1. Increased yield
  2. Enrichment of product
  3. Heat conservation
  4. All (A), (B) & (C)

Correct answer: (D)
All (A), (B) & (C)

259. Refluxing of part of the distillate in a fractionating column is a 'recycling operation', aimed primarily at

  1. Heat conservation
  2. Yield enhancement
  3. Product enrichment
  4. None of these

Correct answer: (C)
Product enrichment

260. Refractories subjected to alternate cycles of heating & cooling are liable to loose their resistance to

  1. Thermal spalling
  2. Slag attack
  3. Fusion under load
  4. CO attack

Correct answer: (A)
Thermal spalling

Previous
Page 26 of 41
Next
Copyright © EngineeringMCQ.com