Oil and fat containing food items are flushed with nitrogen. Why ?
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.
Balance the following chemical equations.
$(a)$ $HNO _{3}+ Ca ( OH )_{2} \longrightarrow Ca \left( NO _{3}\right)_{2}+ H _{2} O$
$(b)$ $NaOH + H _{2} SO _{4} \longrightarrow Na _{2} SO _{4}+ H _{2} O$
$(c)$ $NaCl + AgNO _{3} \longrightarrow AgCl + NaNO _{3}$
$(d)$ $BaCl _{2}+ H _{2} SO _{4} \longrightarrow BaSO _{4}+ HCl$
A shiny brown coloured element $‘X’$ on heating in air becomes black in colour. Name the element $‘X’$ and the black coloured compound formed.
Explain the ''Rancidity'' terms with one example.
In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved.
What do you mean by a precipitation reaction? Explain by giving examples.