Chemistry - Study Mode

[#721] If we burn graphite,
Correct Answer

(B) No residue will be left

Explanation

Solution: If we burn graphite, no residue will be left.

[#722] Lead pencil contains
Correct Answer

(D) Graphite

Explanation

Solution: Lead pencils contain graphite (a form of carbon), not lead. In fact, contrary to what many people believe, lead pencils never were made with lead. The ancient Romans used a writing device called a stylus.

[#723] Highest percentage of carbon is found in which form of coal?
Correct Answer

(A) Anthracite

Explanation

Solution: Highest percentage of carbon is found in anthracite.

[#724] The main source of carbon monoxide is
Correct Answer

(C) Transportation

Explanation

Solution: The main source of carbon monoxide is transportation.

[#725] Highly toxic gas which causes headache, visual difficulty, paralysis and even death is
Correct Answer

(C) CO

Explanation

Solution: Carbon monoxide intoxication can be caused by single or repetitively generated high short-term peaks, and carbon monoxide poisoning is the leading cause of death from poisoning (accidental and intentional).