Why does the colour of copper sulphate solution change when an iron nail is dipped in it ?
When an iron nail is placed in a copper sulphate solution, iron displaces copper from copper sulphate solution forming iron sulphate, which is green in colour.
$\underset{Iron}{\mathop{F{{e}_{(s)}}}}\,+\underset{\begin{smallmatrix}
Copper\text{ }sulphate \\
\left( Blue\text{ }colour \right)~
\end{smallmatrix}}{\mathop{CuS{{O}_{4\left( aq \right)}}}}\,\to \underset{\begin{smallmatrix}
Iron\text{ }sulphate \\
\left( Green\text{ }colour \right)
\end{smallmatrix}}{\mathop{FeS{{O}_{4\left( aq \right)}}}}\,+\underset{Copper}{\mathop{C{{u}_{(s)}}}}\,$
Therefore, the blue colour of copper sulphate solution fades and green colour appears.
In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved.
Why should a magnesium ribbon be cleaned before burning in air ?
What happens when dilute hydrochloric acid is added to iron fillings ? Tick the correct answer.
Write the balanced chemical equation for the following and identify the type of reaction in each case.
$(a)$ Potassium bromide $(aq)$ $+$ Barium iodide$(aq)$ $\rightarrow$ Potassium iodide$(aq)$ $+$ Barium bromide$(s)$
$(b)$ Zinc carbonate$(s)$ $\rightarrow$ Zinc oxide$(s)$ $+$ Carbon dioxide$(g)$
$(c)$ Hydrogen$(g)$ $+$ Chlorine$(g)$ $\rightarrow$ Hydrogen chloride$(g)$
$(d)$ Magnestum $(s)$ $+$ Hydrochloric acid$(aq)$ $\rightarrow$ Magnesium chloride$(aq)$ $+$ Hydrogen $(g)$
What is the difference between displacement and double displacement reactions ? Write equations for these reactions.