Explain the "Reduction'' in terms of gain or loss of oxygen with two examples.
Reduction is the loss of oxygen.
For example :
$(i)$ $\mathop {C{O_2}\, + \,{H_2}\, \to \,CO}\limits_{{\text{Removal of oxygen - reduction}}} \, + \,{H_2}O$
$(ii)$ $\mathop {CuO\, + {H_2}\,\xrightarrow{\Delta }\,Cu}\limits_{{\text{Loss of oxgyen - reduction}}} \, + \,{H_2}O$
In equation $(i)$, $CO_2$ is reduced to $CO$ and in equation $(ii)$, $CuO$ is reduced to $Cu$.
Why is respiration considered an exothermic reaction ? Explain.
Write the balanced equation for the following chemical reactions.
$(i)$ Hydrogen $+$ Chlorine $\to $ Hydrogen chloride
$(ii)$ Barium chloride $+$ Aluminium sulphate $\to $ Barium sulphate $+$ Aluminium chloride
$(iii)$ Sodium $+$ Water $\to $ Sodium hydroxide $+$ Hydrogen
What does one mean by exothermic and endothermic reactions ? Give examples.
What is a balanced chemical equation ? Why should chemical equations be balanced ?
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