Reaction of praseodymium with acids
Praseodymium dissolves readily in dilute sulphuric acid, forming a green solution of Pr(III) ions and hydrogen gas, H2.
2 Pr(s) + 3 H2SO4(aq) 2 Pr3+(aq) + 3 SO42−(aq) + H2(g)
Reaction of praseodymium with air
Praseodymium reacts slowly with oxygen, O2, tarnishing the surface, under normal conditions. Praseodymium can be burned, thereby oxidizing to a mixture of praseodymium oxides with the approximate formula Pr6O11:
12 Pr(s) + 11 O2(g) 2 Pr6O11(s)
Reaction of praseodymium with halogens
Praseodymium reacts with the halogens, forming the corresponding praseodymium(III) halides.
2 Pr(s) + 3 F2(g) 2 PrF3(s) [green]
2 Pr(s) + 3 Cl2(g) 2 PrCl3(s) [green]
2 Pr(s) + 3 Br2(g) 2 PrBr3(s) [green]
2 Pr(s) + 3 I2(g) 2 PrI3(s)
Reaction of praseodymium with water
Praseodymium reacts slowly with cold water, and quite quickly with hot water, forming praseodymium hydroxide, Pr(OH)3, and hydrogen gas (H2).
2 Pr(s) + 6 H2O(l) 2 Pr(OH)3(aq) + 3 H2(g)