The foul smell of dead fish is due to the compound
Correct Answer:
(A)
Amino compounds
Trimethylamine is a tertiary amine that is structurally an amino compound in which every hydrogen atom of ammonia is replaced by a methyl group. The odour (smell) of dead fish is due to the presence of these compounds.
Ques:
72
Which gas is filled at low pressure in a tubelight?
Correct Answer:
(B)
Neon and Mercury vapour
The normal tubelights are filled with mercury vapour with inert gas like argon or neon. An electric current in the gas excites mercury vapour which produces short wave ultraviolet light that causes phosphor coating inside the bulb to glow.
Ques:
73
When kept in air and darkness, which of the following elements glows spontaneously?
Correct Answer:
(B)
White phosphorus
White phosphorus is a waxy, transparent solid. It sublimes if exposed to light. The sublimation is the process by which solid changes directly into a gas when heated, without first changing to a liquid. The White phosphorus is phosphorescent. It gives off a beautiful greenish–white glow.
Ques:
74
Which of the following countries has made it mandatory to blend ethanol with gasoline?
Correct Answer:
(D)
Brazil
Since 1976, the Brazilian Government has made it mandatory to blend ethanol with gasoline and since 2007, the legal blend is around 25% ethanol and 75% gasoline.