Question

(a) Name the changes in the terms of process P, Q, R and S.
(b) Which of the changes are exothermic and endothermic?​

Answer 1

Answer:

P) melting point

Q) boiling point

R) condensation

S) sublimation

Answer 2

(a)

• P:Melting(In this process ,Solid converts into liquid , eg:Ice to water)
• Q:Evaporation(In this process ,Liquid converts into gas, eg:Water to water vapour)
• R:Condensation(In this process, the Gas converts  into Liquid, eg: water vapour to water)
• S:Sublimation(In this process, The Solid converts  into gas, eg: Dry ice into CO₂)

(b)

• P: Endothermic
• Q:Endothermic
• R:Exothermic
• S:Endothermic

Hence, all of these processes except R are endothermic, that is, they all require energy to take place, whereas exothermic reactions release energy after they take place.