Exams › NEET › Chemistry

In which case change in entropy is negative?

1. Evaporation of water
2. Expansion of a gas at constant temperature
3. Sublimation of solid to gas
4. 2H(g) → H2(g)

Correct answer: 2H(g) → H2(g)

Solution

Entropy decreases when two hydrogen atoms combine to form a diatomic molecule (H2) because the system becomes more ordered, reducing randomness.

Related NEET Chemistry questions

• An ideal gas is compressed in a closed container its U?
• Internal energy does not include
• Assertion The change in internal energy and change in heat enthalpy does not depend upon the path by which changes are brought in. Reason Both \( \Delta U \) and \( \Delta H \) are path independent as U and H are state functions.
• Liquid benzene burns in oxygen according to: \( 2 C_{6} H_{6}+15 O_{2} \rightarrow 12 C O_{2}+6 H_{2} O \) If density of liquid benzene is \( 0.88 \mathrm{g} / \mathrm{cc} \) what volume of \( \boldsymbol{O}_{2} \) at \( \mathrm{STP} \) is needed to complete the combustion of 39 cc of liquid benzene?
• When a bomb calorimeter is used to determine the heat of reaction, which property of the system under investigation is most likely to remain constant?
• When heat is given to gas in an isothermal change, the result will be

⚔️ Practice NEET Chemistry free + battle 1v1 →