Question

Differentiate between the following by
giving one example each:
(a) Physical and chemical changes
(b) Exothermic and endothermic reactions
(c) Chemical combination and
decomposition reactions
(d) Oxidation and reduction

Answer 1

Answer:

(a) The difference between a physical reaction and a chemical reaction is composition. In a chemical reaction, there is a change in the composition of the substances in question; in a physical change there is a difference in the appearance, smell, or simple display of a sample of matter without a change in composition.

(b) In simple terms, the endothermic reactions absorb energy from the surrounding that is in the form of heat. ... On the other hand, an exothermic reaction releases energy into the surrounding of the system.

(c) Reactions in which many reactants combine to give one product are called combination reactions whereas, in decomposition one reactant breaks down in many products.

(d) Oxidation occurs when a reactant loses electrons during the reaction. Reduction occurs when a reactant gains electrons during the reaction. This often occurs when metals are reacted with acid.

Explanation:

Answer 2

Answer:

a.Physical Change Chemical Change

In a physical change, no new substance is formed. A chemical change is always accompanied by one or more new substance

b.The difference between endothermic and exothermic reactions lies in the words themselves. "Thermic" refers to heat, just as in the word "thermometer." "Exo" means "outside" and "endo" means "inside." Thus, an endothermic reaction pulls heat into an object or area, while an exothermic reaction expels heat.

c.It is a chemical reaction in which two or more reactants combine with each other to form a new single product. It releases heat during the chemical reaction. This means that it is exothermic . It is a chemical reaction in which one reactant breaks down into simpler compounds.

d.Oxidation occurs when a reactant loses electrons during the reaction. Reduction occurs when a reactant gains electrons during the reaction. This often occurs when metals are reacted with acid