Which among the following changes are exothermic or endothermic in nature?
(a) Decomposition of ferrous sulphate
(b) Dilution of sulphuric acid
(c) Dissolution of sodium hydroxide in water
(d) Dissolution of ammonium chloride in water
NCERT Class X
Science - Exemplar Problems
Chapter_Chemical Reactions And Equations
Answers
answer :
(a) endothermic reaction
explanation : To decompose ferrous sulphate , heat is required to decompose the compound into its components. hence, it is an endothermic reaction
(b) exothermic reaction
explanation : sulphuric acid is one of the strongest acid. so, when we dilute the sulphuric acid, it evolves huge amount of heat. hence, dilution of sulphuric acid is an exothermic reaction.
(c) exothermic reaction
explanation : sodium hydroxide is one of the strongest base. so,when we add the NaOH into water, huge amount of heat evolves. hence, dissolution of sodium hydroxide is an exothermic reaction.
(d) endothermic reaction
explanation : amonium chloride is very weak acid. obviously it is soluble in water but heat is absorbed during dissolution in water. hence, dissolution of amonium chloride is an endothermic reaction.
a) Endothermic reaction
b) Exothermic reaction
c) Exothermic reaction
d) Endothermic reaction