Chemistry - Study Mode

[#1011] The following are the half lives of four active isotopes. Which one of the following is the most dangerous to handle?
Correct Answer

(C) 0.01 minute

Explanation

Solution: 0.01 minute is the most dangerous to handle.

[#1012] The gas used for artificial ripening of green fruit is
Correct Answer

(A) ethylene

Explanation

Solution: Ethylene gas, acetylene gas liberated from calcium carbide, and ethephon are some of the commercial ripening agents used successfully in the trade and they have been widely studied for their effectiveness on initiating and accelerating the ripening process and their effect on fruit quality and health related issues. Green fruits are ripened by ethylene gas.

[#1013] Zone refining is used for the purification of
Correct Answer

(B) Ge

Explanation

Solution: Zone refining is a very useful method to get metals with very high purity such as silicon and germanium. It is also referred to as zone melting, floating zone process, and travelling melting zone.

[#1014] The main chemical constituent of the oil of cardamom which is responsible for flavour of this oil is
Correct Answer

(A) cineole

Explanation

Solution: The main chemical constituent of the oil of cardamom which is responsible for flavour of this oil is cineole.

[#1015] The molecule which has the highest percentage of ionic character among the following is
Correct Answer

(B) HF

Explanation

Solution: HF has the highest percentage of ionic character because F has the greatest electronegativity. F, Cl, I, and Br are all in the same group so that means their electronegativity (and thus percentage of ionic character) decreases as they go down the group in the periodic table.