What is the difference between strontium chloride and lithium chloride?
Strontium chloride is a compound of lithium and chlorine with the formula SrCl2.
Lithium chloride is a compound of lithium and chlorine with the formula LiCl.
Why is there only one chloride ion for the molecules lithium chloride and potassium chloride but two chlorides for barium chloride strontium chloride and calcium chloride?
In an ionic compound the charges of all the ions must balance out to zero. The chloride ion has a charge of -1. Lithium and potassium ions both have a +1 charge. So these ions will combine in a 1:1 ration. By contrast, barium, strontium, and calcium all form ions with a 2+ charge, so in order to balance the charges, chloride ions must combine with these metals in a 2:1 ratio.