Question

When $NaBr\left( s \right)$ is added to a solution of $CuS{O_4}$ and water, what colour should it change? Why would $AgBr\left( s \right)$ not produce a colour change in the same solution?

Answer 1

Copper sulphate is blue in colour. Sodium bromide is soluble in water. Thus, when sodium bromide is added to a solution of copper sulphate and water the reaction will happen to form a cupric bromide along with the sodium sulphate. Silver bromide is not soluble in water and there is no chemical reaction with $CuS{O_4}$ and water.

Complete Step By Step Answer:
Sodium bromide was represented by the chemical formula of $NaBr$ , which is soluble in water. Thus, when sodium bromide is added to a solution of copper sulphate and water, it leads to the formation of cupric bromide along with the sodium sulphate. The formula of cupric bromide is $CuB{r_2}$ which is in grey or black colour.
$NaBr + CuS{O_4} \to N{a_2}S{O_4} + CuB{r_2}$
Thus, the blue colour of copper sulphate changes to grey or black colour.
Silver bromide is represented by the chemical formula of $AgBr$ it is not soluble in water. Thus, when silver bromide is added to copper sulphate and water there will be no chemical reaction and there is no colour change. The yellow crystals of silver bromide settle down. Thus, $AgBr$ does not produce any colour in the same solution.

Note:
Sodium bromide is an inorganic salt formed by the combination of sodium which is a metal and bromine which is a non-metal. Sodium bromide was represented by the chemical formula of $NaBr$ , which is soluble in water and leads to colour change in chemical reaction. Whereas $AgBr$ is not soluble in water leads to unreactivity in the same solution.