Reaction of potassium with acids
Potassium dissolves readily in dilute sulphuric acid, forming potassium ions and hydrogen gas, H2.
2 K(s) + H2SO4(aq) 2 K+(aq) + SO42−(aq) + H2(g)
Reaction of potassium with air
Potassium reacts slowly with oxygen, O2, tarnishing the surface, under normal conditions.
If heated with a calculated amount of oxygen, potassium peroxide is formed :
2 K(s) + O2(g) K2O2(s)
If heated with an excess amount of oxygen, potassium superoxide is formed :
K(s) + O2(g) KO2(s)
Reaction of potassium with halogens
Potassium reacts with the halogens, forming the corresponding potassium halides.
2 K(s) + F2(g) 2 KF(s)
2 K(s) + Cl2(g) 2 KCl(s) [white]
2 K(s) + Br2(g) 2 KBr(s)
2 K(s) + I2(g) 2 KI(s)
Reaction of potassium with hydrogen
Potassium reacts with hydrogen, forming potassium hydride .
2 K(s) + H2(g) 2 KH(s)
Reaction of potassium with water
Potassium reacts wiolently with water, forming potassion hydroxide, KOH, and hydrogen gas, H2.
2 K(s) + 2 H2O(l) 2 KOH(aq) + H2(g)
Method 3500-K C Inductively Coupled Plasma Method . A portion of the sample is digested in a combination of acids. The digest is aspirated into an 8,000 K argon plasma where resulting light emission is quantified for 30 elements simultaneously.
Method limit of detection in water = 1.0 mg/L
Method limit of detection in soil = 100.0 mg/kg