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 hydrogen gas with oxygen gas to form water vapor at room temperature

e. the dissolution of HCl(g) in water to form concentrated hydrochloric acid