Question

Which of the following processes are spontaneous:

(a) the melting of ice cubes at 10 C and 1 atm pressure
(b) separating a mixture of N₂ and O₂ into two separate samples, one that is pure N₂ and one that is pure O₂
(c) alignment of iron filings in a magnetic field
(d) the reaction of sodium metal with chlorine gas to form sodium chloride
(e) the dissolution of HCl(g) in water to form concentrated hydrochloric acid

Answer 1

The melting of ice cubes, the reaction of sodium metal with chlorine gas, and the dissolution of HCl in water are spontaneous processes. The correct options are (a), (d), and (e).

Step-by-step explanation:

Spontaneous processes are those that occur naturally without requiring any external influence. Let's analyze each of the given processes to determine if they are spontaneous:

1. (a) The melting of ice cubes at 10°C and 1 atm pressure is a spontaneous process because it occurs at a temperature above the freezing point of water and does not require any external influence.
2. (b) Separating a mixture of N₂ and O₂ into two separate samples, one that is pure N₂ and one that is pure O₂ is a nonspontaneous process because it requires external work and energy to separate the gases.
3. (c) The alignment of iron filings in a magnetic field is a nonspontaneous process because it requires external work and energy to align the filings.
4. (d) The reaction of sodium metal with chlorine gas to form sodium chloride is a spontaneous process because it occurs naturally and releases energy in the form of heat and light.
5. (e) The dissolution of HCl(g) in water to form concentrated hydrochloric acid is a spontaneous process because it occurs naturally and releases energy.

Therefore, the correct options are (a), (d), and (e).