A shiny brown coloured element $‘X’$ on heating in air becomes black in colour. Name the element $‘X’$ and the black coloured compound formed.
$‘X’$ is copper $(Cu)$ and the black-coloured compound formed is copper oxide $(CuO)$. The equation of the reaction involved on heating copper is given below.
$\mathop {2Cu\,}\limits_{(Shiny\,brown\,in\,\,colour)} + \,{O_2}\,\xrightarrow{{Heat}}\mathop {2CuO}\limits_{(Black\,in\,\,colour)} $
Why should a magnesium ribbon be cleaned before burning in air ?
Oil and fat containing food items are flushed with nitrogen. Why ?
Why does the colour of copper sulphate solution change when an iron nail is dipped in it ?
Explain the "Oxidation'' in terms of gain or loss of oxygen with two examples.
Write the balanced chemical equations for the following reactions.
$(a)$ Calcium hydroxide $+$ Carbon dioxide $\rightarrow$ Calcium carbonate $+$ Water
$(b)$ Zinc $+$ Silver nitrate $\rightarrow$ zinc nitrate $+$ Silver
$(c)$ Aluminium $+$ Copper chloride $\rightarrow$ Aluminium chloride $+$ Copper
$(d)$ Barium chloride$+$ Potassium sulphate $\rightarrow$ Barium sulphate $+$ Potassium chloride