Kainite
MgSO₄,KCI,3H₂O, occurs in the stassfurt salt deposits as beds. Used as a source of K salts and as fertilizer.

Kieserite
A mineral form of magnesium sulphate monohydrate, MgSO₄.H₂O.

Killed spirits
Refers to zinc (II) chloride solution used as a flux for solder, so called because it is made by adding a zinc to hydrochloric acid (‘spirits of salt’)

Lawrencium
A radioactive transuranic element of actinicle series obtained by bombardment of californium with accelerated 10 B ions. Symbol: Lr; a.n. 103.

Kovar
A trade name for an alloy of iron, cobalt, and nickel with an expansivity similar to that of glass. It is therefore used in making glass-to-metal seals, especially in circumstances in which a temperature variation can be expected.

Krypton
A colourless odourless monatomic element of the rare-gas group. It is now known to form compounds. It occurs in minute quantities (0.01%) by volume in air. Krypton finds use in fluorescent lights.

Law of multiple proportions
If two elements form more than one compound, the weights of one of the elements which combine with a given weight of the other element are related to each other as integer numbers.

Latent heat
The heat required by a substance or a system without an accompanying rise in temperature during a change of state form solid to liquid or liquid to gas.

Latex
A stable aqueous dispersion of a polymer. Originally applied to natural rubber latex form the bark of certain trees. Many synthetic rubbers and polymers (e.g., PVC, polyacrylates) are produced as latexes. Latexes may be used for direct manufacture of rubber and plastic goods, by dipping moulding, spreading, electrodeposting and in preganating (e.g., textiles, adhesives, paints.

Leaching
Refers to the washing out of a soluble material from an insoluble solid using a solvent. This is often done in batch tanks or by dispersing th4e crushed solid in a liquid.