Question

Consider the following changes:

(a) COCl₂​(g)→CO(g) + Cl₂​(g)
(b) N₂​(g)→N₂​(l)
(c) CO(g) + H2₂O(g) →H₂​(g)+CO₂(g)
(d) Ca₃​P₂(s)+6H₂​O(l) →3Ca(OH)₂​(s)+2PH₃​(g)
(e) 2CH₃​OH(l) +3O₂​(g) →2CO₂​(g) +4H₂​O(l)
(f) I₂(s)→I₂​(g)

At constant temperature and pressure, in which of these changes is work done by the system on the surroundings?

Answer 1

In the given changes, the reaction (f) 2CH₃OH(l) +3O₂​(g) →2CO₂​(g) +4H₂​O(l) does work on the surroundings. The combustion of methanol (CH₃OH) is exothermic and results in an increase in volume, leading to work done on the surroundings.

option e is the correct

Step-by-step explanation:

In the given changes, the reaction that does work on the surroundings is (f) 2CH₃OH(l) +3O₂​(g) →2CO₂​(g) +4H₂​O(l). In this reaction, the system releases energy in the form of heat and work.

The combustion of methanol (CH₃OH) to form carbon dioxide (CO₂) and water (H₂O) is exothermic, meaning heat is released. Additionally, during this reaction, the volume of the system increases as the gaseous products are formed, resulting in work being done on the surroundings.