The cup shown listed below provides an instance of tarnish, a invernessgangshow.netical readjust caused through the reaction ofsilver steel with hydrogen sulfide gas. Hydrogen sulfide gas is produced by some commercial processes, or as a an outcome of decaying animal or tree materials:

\<2 \ceAg + \ceH_2S \rightarrow \ceAg_2S + \ceH_2\>

The tarnish can be gotten rid of using a variety of polishes, yet the procedure also removes a little amount the silver in addition to the tarnish.

You are watching: Which of the following is a single replacement reaction

Figure $$\PageIndex1$$: A tarnished silver cup. (CC BY-NC; CK-12)

A single-replacement reaction is a reaction in i m sorry one element replaces a comparable element in a compound. The general kind of a single-replacement (also referred to as single-displacement) reaction is:

\<\ceA + \ceBC \rightarrow \ceAC + \ceB\>

In this basic reaction, facet $$\ceA$$ is a metal and also replaces element $$\ceB$$(also a metal) in the compound. As soon as the aspect that is doing the replacing is a nonmetal, it need to replace an additional nonmetal in a compound, and also the basic equation becomes:

\<\ceY + \ceXZ \rightarrow \ceXY + \ceZ\>

(Where $$\ceY$$ is a nonmetal and replaces the nonmetal $$\ceZ$$ in the compound with $$\ceX$$.)

### Hydrogen Replacement

Many metals react quickly with acids and when they do so, among the commodities of the reaction is hydrogen gas. Zinc reacts with hydrochloric acid to produce aqueous zinc chloride and hydrogen (figure below).

\<\ceZn \left( s \right) + 2 \ceHCl \left( aq \right) \rightarrow \ceZnCl_2 \left( aq \right) + \ceH_2 \left( g \right)\>

In a hydrogen instead of reaction, the hydrogen in the acid is replaced by an active metal.

Figure $$\PageIndex2$$: Zinc steel reacts with hydrochloric acid to provide off hydrogen gas in a single-displacement reaction.

See more: What Is The Charge On Carbon (C), Formal Charge

(CC BY-NC; CK-12)

Some steels are for this reason reactive the they are qualified of replacing the hydrogen in water. The assets of together a reaction space the steel hydroxide and also hydrogen gas. All team 1 steels undergo this form of reaction. Salt reacts vigorously through water to produce aqueous salt hydroxide and also hydrogen (see figure below).