Question

Write balanced chemical equations for the following reactions: (questions)

(a) Burning of coal


(b) A piece of zinc metal is added to copper sulphate solution


(c) Solutions of sodium sulphate and barium chloride are mixed
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Answer 1

Answer:

This chapter deals with various chemical reactions, their examples and corresponding chemical equations. A chemical reaction is a process in which new substances with new properties are formed. It involves rearrangement of atoms and breaking of chemical bonds.

In a chemical reaction mainly there will be two sides, one is reactant side and the other one is the product side. Two reactants combine to form products or reactants are transformed into products in a chemical reaction. The method of representing a chemical reaction with the help of symbols and formulae of the substance involved is known as chemical equations.

Answer 2

Explanation:

A. answer.

Following chemical reactions takes place in the combustion of coal with the release of heat: C + O2 = CO2 + 8084 Kcal/ Kg of carbon (33940 KJ/Kg) S + O2 = SO2 + 2224 Kcal/Kg of sulfur (9141 KJ/Kg) 2 H2 + O2 = 2 H2O + 28922 Kcal/Kg of hydrogen (142670 KJ/Kg)

B. answer.

Double displacement reactions generally take place in aqueous solutions in which the ions precipitate and there is an exchange of ions. For example, on mixing a solution of barium chloride with sodium sulphate, a white precipitate of barium sulphate is immediately formed. These reactions are ionic in nature.

C. answer.

When aqueous solution of BaCl2 and Na2SO4 are mixed, they react with each other and form aqueous solution of NaCl with white white precipitate of BaSO4. The above reaction is called as precipitate reaction or double displacement reaction.