what are these substances' odour?
156228
Salts do have odor. It is not necessary that only volatile matter would have odor. As ragandre said the salts you have said KI,NaCl,Epsom salt have faint odor.
932845
acid\ngas naphtha\noxygen  and hydrogen\nacid\nacid
402346
The odor of farts comes from small amounts of hydrogen sulfide gas and mercaptans in the mixture. These compounds contain sulfur. Nitrogen-rich compounds such as skatole and indole also add to the stench of farts. The more sulfur-rich your diet, the more sulfides and mercaptans will be produced by the bacteria in your guts, and the more your farts will stink. Foods such as cauliflower, eggs and meat are notorious for producing smelly farts, whereas beans produce large amounts of not particularly stinky farts.
1039863
sweat mainly consists  of sodium chloride (commonly known as salt) and urea in solution, the chemicals or odorants 2-methylphenol and 4-methylphenol.\nwhen it is secreted out of the body,it doesn't smell.but after sometime the bacteria present in the air comes in contact and due to bacterial attack,some reactions takes place and thereby producing alcohols,acids which are smelly!
914014
its called a flehmen response it helps smelling certain substances. See link for info so I don't have to write it all here.
746094
Certain things give off a different smell when heated but mostly I don't think you can differentiate. The sensation of smell is caused by particles of the thing in question not by chemicals released.
981635
"These substances" refers to what?\n\nThe product of combustion include the oxides of carbon-mono and di, water vapor, unburned hydrocarbons and mineral ash.
824994
Sorry It's not our ball game we are mearly small fish in a big pond.\n(sniff? sniff?)\nWhat is that smell??
1002183
Concentrated Nitric Acid and copper.  Be careful.  Nasty stuff... really!
169214
Odors are also called smells. The term stench or pong is used to describe an unpleasant odor. The term fragrance or aroma is used primarily by the food and cosmetic industry to describe a pleasant odor.\n\nOdors that are mostly perceived as "pleasant":\n\nflowers, trees, some plants, baked goods, cologne, mint, fresh fruit \nOdors that are mostly perceived as "unpleasant":\n\nbad breath, foot odor, feces, flatulence, vomit, and rotting organic matter \nThe study of odors is a growing field, but is a complex and difficult one. The human olfactory system can detect many thousands of scents based on only very minute airborne concentrations of a chemical. The sense of smell of many animals is even better. Some fragrant flowers give off odor plumes that move downwind, and are detectable by bees more than a kilometer away.\n\nPheromones are odors that are deliberately used for communication. A female moth may release a pheromone that can entice a male moth from several kilometers. Honeybee queens constantly release pheromones that regulate the activity of the hive. Workers can release such odors to call other bees into an appropriate cavity when a swarm moves in, or to "sound" an alarm when the hive is threatened.
482702
Carbon Dioxide\nMethane\nWater Vapor
573959
pheromones.. sex hormones . it comes from males and females usaly from the sweat glands
290954
probably not its own smell.
727648
Rotten egg smell indicates hydrogen sulfite production...protein that is being converted anerobically....Flush it with bleach and begin again.
989446
what foregin substance are you talking about first...
933669
aldehyde\nthe name of the compound is propionaldehyde
158334
Interesting question.  I'd suggest hydrogen sulfide (rotten eggs), putrescine, and cadaverine.  Any small (say, 1-5 carbon) alkyl mercaptan or thiol smells pretty dang bad.  \n\nIf the army were to go to all the trouble to weaponize something that smells bad, they'd rather kill you than make you vomit.  Usually.