what is displacement reaction
Answers
Answer:
A single-displacement reaction, is a chemical reaction in which one element is replaced by another in a compound. It can be represented generically as:
Copper displaces dissolved silver from a solution. When a copper wire is dipped in a silver nitrate solution, solid silver precipitates out.
A + B-C → A-C + B
This will most often occur if A is more reactive than B, thus giving a more stable product. A and B must be either:
Different metals (hydrogen's behavior as a cation renders it as a metal here), in which case C represents an anion; or
Halogens, in which case C represents a cation.
In either case, when AC and BC are aqueous compounds (which is usually the case), C is a spectator ion.
In the activity or reactivity series, the metals with the highest propensity to donate their electrons to react are listed first, and the most unreactive metals are listed last. Therefore, a metal higher on the list is able to displace anything on the list below it.[1] The order of activity for metals, from most reactive to least reactive, is: Li, K, Sr, Na, Ca, Mg, Al, Zn, Cr, Fe, Cd, Co, Ni, Sn, Pb, H, Sb, As, Bi, Cu, Hg, Ag, Pd, Pt, and Au. Similarly, the halogens with the highest propensity to acquire electrons are the most reactive. The activity series for halogens, from highest to lowest, is: F, Cl, Br, and I.[2]
Due to the free state nature of A and B, all single displacement reactions are also oxidation-reduction reactions, where the key event is the movement of electrons from one reactant to another.[3] When A and B are metals, A is always oxidized and B is always reduced. Since halogens prefer to gain electrons, A is reduced (from 0 to −1) and B is oxidized (from −1 to 0) when A and B represent those elements.
A and B may have different charge as ions and therefore some balancing of the equation may be necessary. For example, the reaction between silver nitrate, AgNO3 (which contains an Ag+ ion), and zinc, Zn, forms silver, Ag, and zinc nitrate, Zn(NO3)2 (which contains a Zn2+ ion).
2AgNO
3
(aq) + Zn
(s) → 2Ag
(s) + Zn(NO
3)
2
(aq)
All simple metal with acid reactions are single displacement reactions. For example, the reaction between magnesium, Mg, and hydrochloric acid, HCl, forms magnesium chloride, MgCl2, and hydrogen, H2.
Mg(s) + 2 HCl(aq) → H2(g) + MgCl2(aq)
Answer:
A single-displacement reaction, is a chemical reaction in which one element is replaced by another in a compound. It can be represented generically as: A + B-C → A-C + B This will most often occur if A is more reactive than B, thus giving a more stable product.