When it is exposed to sunlight, silver chloride breaks down into silver and chlorine. What is the correct equation for this decomposition reaction?

The correct equation for the decomposition reaction of Silver chloride :

2AgCl(s)⇒2Ag(s)+Cl₂(g)

Given

Silver chloride breaks down into Silver and Chlorine.

Required

The correct equation

Solution

Decomposition reaction : a single reactants breaks down into 2 or more products. The reaction is the reverse of synthesis reaction

General formula :

AB ⇒ A + B

So for decomposition of Silver chloride :

2AgCl(s)⇒2Ag(s)+Cl₂(g)

you need to take a look at the periodic system in order to sort these elements into pairs that would most likely exhibit similar chemical properties. first, you need to find elements that are found in the same group (groups are vertical in the periodic system), and then to see whether they have the same valence number. if they meet these criteria, they will have similar properties.

the first pair: ne (neon) and kr (krypton), are noble gases found in group 8

the second pair: li (lithium) and k (potassium), found in group 1

the third pair: s (sulfur) and te (tellurium), found in group 6