Explain the following terms with one example each.
[question] Question. Explain the following terms with one example each. (a) Corrosion (b) Rancidity [/question] [solution] solution: (a) Corrosion- Corrosion is defined as a process where materials, usually metals, deteriorate as a result of a chemical reaction with air, moisture, chemicals, etc. For example, iron, in the presence of moisture, reacts with oxygen to form hydrated iron oxide. $4 \mathrm{Fe}+3 \mathrm{O}_{2}+\mathrm{nH}_{2} \mathrm{O} \rightarrow 2 \mathrm{Fe}_{2} \mathrm{O}_{3} \c...
Oil and fat containing food items are flushed with nitrogen.
[question] Question. Oil and fat containing food items are flushed with nitrogen. Why? [/question] [solution] solution: Nitrogen is an inert gas and does not easily react with these substances. On the other hand, oxygen reacts with food substances and makes them rancid. Thus, bags used in packing food items are flushed with nitrogen gas to remove oxygen inside the pack. When oxygen is not present inside the pack, rancidity of oil and fat containing food items is avoided. [/solution]...
Why do we apply paint on iron articles?
[question] Question. Why do we apply paint on iron articles? [/question] [solution] solution: Iron articles are painted because it prevents them from rusting. When painted, the contact of iron articles from moisture and air is cut off. Hence, rusting is prevented. Their presence is essential for rusting to take place. [/solution]...
A shiny brown-coloured element ' $X$ ' on heating in air becomes black in colour.
[question] Question. A shiny brown-coloured element ' $\mathrm{X}$ ' on heating in air becomes black in colour. Name the element ' $\mathrm{X}^{\prime}$ and the black coloured compound formed. [/question] [solution] solution: $' X^{\prime}$ is copper $(\mathrm{Cu})$ and the black-coloured compound formed is copper oxide $(\mathrm{CuO})$. The equation of the reaction involved on heating copper is given below. [/solution]...
Explain the following in terms of gain
[question] Question. Explain the following in terms of gain or loss of oxygen with two examples each. (a) Oxidation (b) Reduction [/question] [solution] solution: (a) Oxidation is the gain of oxygen. For example, In equation (i), $\mathrm{H}_{2}$ is oxidized to $\mathrm{H}_{2} \mathrm{O}$ and in equation (ii), $\mathrm{Cu}$ is oxidised to $\mathrm{CuO}$. (b) Reduction is the loss of oxygen. For example, In equation (i), $\mathrm{CO}_{2}$ is reduced to $\mathrm{CO}$ and in equation (ii), $\mathrm...