Which of the following compounds cannot exist?

Question

A. C2H2
B. C4H8
C. C2H3
D. C2H4

Answer 1

Odd numbers of hydrogens are not found. The answer is C.

Answer 2

Acetylene (C2H2) is not an air gas, but a synthesis gas generally produced from the reaction of calcium carbide with water. It was burnt in "acetylene lamps" to light homes and mining tunnels in the 19th century. A gaseous hydrocarbon, it is colorless, has a strong garlic odor, is unstable, highly combustible, and produces a very hot flame (over 3000°C or 5400°F) when combined with oxygen.

C4H8 Butylene

C2H3 and C3Hg, where C:H=7.98 and C:0+N=46.3 . In cannel coals the prevailing constituents are the spores of cryptogamic See also:

PLANTS
plants, See also:
ALGAE
algae being rare or in many cases absent . By making very thin sections and employing high magnification (1000-1200 diameters), Renault has been enabled to detect numerous forms of bacilli in the woody parts preserved in See also:
COAL
coal, one of which, Micrococcus See also:
CARBO
carbo, bears a strong resemblance to the living Cl'adolhrix found in trees buried in See also:
PEAT (possibly connected with Med. Lat. petia, pecia, piece, ultimately of Celtic origin; cf. O. Celt. pet, O. Ir. pit, Welsh peth, portion)
peat bogs .

Ethylene - C2H4 - is used for accelerating the ripening of bananas, and maturing the color of citrus fruits. It is also used to increase the growth rate of seedlings, vegetables, and fruit trees; in oxyethylene welding and cutting of metals; in manufacture of mustard gas, ethylene oxide, ethylene alcohol, polyethylene and other plastics; and as an inhalation anesthetic.

Answer 3

No simple hydrocarbon can contain an odd number of H atoms, so it's C.