Question

State the kind of chemical reactions in the following examples in terms of loss and gain

of energy: (i) Digestion of food in stomach (ii) Combustion of coal in air (iii) Heating of

limestone.​

Answer 1

Answer:

Magnesium is an extremely reactive metal. When stored, it reacts with oxygen to form a layer of magnesium oxide on its surface. This layer of magnesium oxide is quite stable and prevents further reaction of magnesium with oxygen. The magnesium ribbon is cleaned by sand paper for removing this layer so that the underlying metal can be exposed to air.

Answer 2

Explanation:

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