Oil and fat containing food items are flushed with nitrogen. Why?

Explain the "Reduction" in terms of gain or loss of oxygen with two examples.

Explain the term 'Rancidity' with one example.

Explain the term 'Corrosion' with one example.

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 $(g)$
$(d)$ Magnesium $(s) +$ Hydrochloric acid $(aq) \rightarrow$ Magnesium chloride $(aq) +$ Hydrogen $(g)$

What do you mean by a precipitation reaction? Explain by giving examples.