Water is the enabler of fast oxidation of iron. So freshwater will also cause rust. However, salt water (sea water) is a very good conductor (lots of dissociated ions) and so there are a number of electrolysis reactions that tremendously accelerate corrosion in salt water. This effect can be reversed by using a metal (like zinc) which causes the current to be reversed and in effect the zinc corrodes rapidly, protecting the iron.

Correct Option: B

Water is the enabler of fast oxidation of iron. So freshwater will also cause rust. However, salt water (sea water) is a very good conductor (lots of dissociated ions) and so there are a number of electrolysis reactions that tremendously accelerate corrosion in salt water. This effect can be reversed by using a metal (like zinc) which causes the current to be reversed and in effect the zinc corrodes rapidly, protecting the iron.

White phosphorous is kept under water because it reacts with oxygen but not water. Besides, it is insoluble in water. It presents a significant fire hazard due to its extreme reactivity with atmospheric oxygen.

Correct Option: B

White phosphorous is kept under water because it reacts with oxygen but not water. Besides, it is insoluble in water. It presents a significant fire hazard due to its extreme reactivity with atmospheric oxygen.

Nitrous oxide is one of the more well-known anesthetic gases, and has been in use for around 200 years. Unlike some other anesthetics, this compound can be used both for inducing unconsciousness and pain control. Chloroform is more potent and more toxic than ether. Its use as an anaesthetic decreased with increased experience and knowledge of its dangers.

Correct Option: B

Nitrous oxide is one of the more well-known anesthetic gases, and has been in use for around 200 years. Unlike some other anesthetics, this compound can be used both for inducing unconsciousness and pain control. Chloroform is more potent and more toxic than ether. Its use as an anaesthetic decreased with increased experience and knowledge of its dangers.

Octane rating or octane number is a standard measure of the performance of a motor or aviation fuel. The higher the octane number, the more compression the fuel can withstand. Isooctane (upper) has an octane rating of 100 whereas n-heptane has an octane rating of 0.

Correct Option: D

Octane rating or octane number is a standard measure of the performance of a motor or aviation fuel. The higher the octane number, the more compression the fuel can withstand. Isooctane (upper) has an octane rating of 100 whereas n-heptane has an octane rating of 0.

Cast Iron is a hard, brittle, nonmalleable ironcarbon alloy, cast into shape. It contains 2 to 4.5 percent carbon, 0.5 to 3 percent silicon, and lesser amounts of sulfur, manganese, and phosphorus.

Correct Option: D

Cast Iron is a hard, brittle, nonmalleable ironcarbon alloy, cast into shape. It contains 2 to 4.5 percent carbon, 0.5 to 3 percent silicon, and lesser amounts of sulfur, manganese, and phosphorus.