what is meant by double decomposition ?

Answer 1

Double decomposition reactions occur when two reactants are each decomposed, or broken up, into a cation (positive ion) and an anion (negative ion). These ions recombine to form two or more products. The formation of insoluble AgCl(s) drives the following double decomposition reactions to completion: AgNO3(aq) + NaCl(aq) → NaNO3(aq) + AgCl(s) and Ag2SO4(aq) + 2NH4Cl(aq) → (NH4)2SO4(aq) + 2AgCl(s).

Complete reactions between soluble ionic compounds can also be driven by the formation of gases. Once a gas bubbles and escapes from an ion-containing solution, the gas cannot participate in a reverse reaction. In the following reaction, carbonic acid (H2CO3) dissociates into water and carbon dioxide gas. Because carbon dioxide (CO2) is not very soluble in water, the CO2 gas bubbles away, driving the ionic reaction forward: H2CO3(aq) → H2O + CO2(g).

Formation of a covalently bonded product may also drive an ionic reaction to completion. Such a reaction may be generally represented as follows: X+ + :Y- → X:Y (where : represents an electron pair).

Answer 2

Double Decomposition Reactions were reaction in which the two elements of two different chemical substance interchange their places, or in other words the reaction in which a more reactive element displaces an another less reactive element from a compound. And after that the displaced element occupies the place of other element in second compound. the most popular examples were
CaCl2 + 2AgNO3 --> 2AgCl + Ca(NO3)2
Here one product is insoluble in water (solution) and one is soluble.
BaCl 2 + Ag2SO 4 = BaSO 4 + AgCl
Here both the initial substances were soluble in water and both the products are insoluble in water.
Double decomposition is an old-fashioned phrase, which does not actually mean what it says. A double decomposition reaction was said to have taken place when two soluble substances were reacted together, and two new substances were created.

Answer 3

Double decomposition is an old-fashioned phrase, which doesn't actually mean what it says. The idea was that both substances when added together decomposed, or broke down. The modern word is "precipitation". A double decomposition reaction is said to have taken place when two soluble substances are reacted together, and a new, insoluble, substance is created which precipitates. Two ions are left in solution as well.

Answer 4

Double Decomposition Reaction :- The reaction in which the two elements interchange their places from the compounds , or in other words the reaction in which a more reactive element displaces an another less reactive element from a compound. And after that the displaced element occupies the place of that element. For ex:-
BaCl 2 + H 2SO 4 = BaSo 4 + HCl

Answer 5

decomposition twice

Answer 6

VIPUL's ansswer is correct......