Chemistry - Study Mode

[#626] Glycol is added to aviation gasoline because it
Correct Answer

(C) Prevents freezing of petrol

Explanation

Solution: Ethylene glycol (IUPAC name: ethane-1,2-diol) is an organic compound widely used as an automotive antifreeze and a precursor to polymers. In its pure form, it is an odorless, colourless, syrupy, sweettasting liquid. Ethylene glycol is toxic, and ingestion can result in death. Due to its low freezing point ethylene glycol resists freezing. A mixture of 60% ethylene glycol and 40% water freezes at -45 degree C (-49 degree F). Diethylene glycol behaves similarly. It is used as a deicing fluid for windshields and aircraft. The antifreeze capabilities of ethylene glycol have made it an important component of vitrification (anticrystallization) mixtures for low-temperature preservation of biological tissues and organs.

[#627] Which is the heaviest metal among the following?
Correct Answer

(A) Gold

Explanation

Solution: Gold is the heaviest metal among the following.

[#628] The wire of flash bulbs is made up of
Correct Answer

(A) Mg

Explanation

Solution: Magnesium metal is used for the preparation of the wire of flash bulb.

[#629] Which among the following is found in chlorophyll ?
Correct Answer

(B) Mg 2+

Explanation

Solution: Chlorophyll is the green pigment found in most plants, which is responsible for light absorption to provide energy by photosynthesis. Chlorophyll contains magnesium ion.

[#630] Among the following the hardest metal is
Correct Answer

(D) Tungsten

Explanation

Solution: Tungsten is the hardest metal among the following.