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.
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$(g)$
$(d)$ Magnestum $(s)$ $+$ Hydrochloric acid$(aq)$ $\rightarrow$ Magnesium chloride$(aq)$ $+$ Hydrogen $(g)$
Explain the "Reduction'' in terms of gain or loss of oxygen with two examples.
What is the difference between displacement and double displacement reactions ? Write equations for these reactions.
Why does the colour of copper sulphate solution change when an iron nail is dipped in it ?
Why is respiration considered an exothermic reaction ? Explain.