Shortages (in the technical sense) may be caused by: 1  Price ceilings, a type of price control which involves a government-imposed limit on the price of a product service. 2  Anti-price gouging laws. 3  Government ban on the sale of a product or service, such as prostitution or certain recreational drugs.
Noun. 1. addition reaction-a chemical reaction in which one molecule is added to another. chemical reaction, reaction - (chemistry) a process in which one or more substances are changed into others; there was a chemical reaction of the lime with the ground water. 1  Facebook. 2  Twitter.
A typical modern aldol addition reaction, shown above, might involve the nucleophilic addition of a ketone enolate to an aldehyde. Once formed, the aldol product can sometimes lose a molecule of water to form an Î±,Î²-unsaturated carbonyl compound. This is called aldol condensation.A variety of nucleophiles may be employed in the aldol reaction, including the enols, enolates, and enol ethers of ketones, aldehydes, and many other carbonyl compounds. The electrophilic partner is usually an aldehyde or ketone (many variations, such as the Mannich reaction, exist). typical modern aldol addition reaction, shown above, might involve the nucleophilic addition of a ketone enolate to an aldehyde. Once formed, the aldol product can sometimes lose a molecule of water to form an Î±,Î²-unsaturated carbonyl compound. This is called aldol condensation.