Before balancing the chemical reaction, let’s first write the chemical formula of each of the compounds involved in the reaction.
Nickel Chloride Dihydrate
• Nickel is a metal. Its most common oxidation state is +2 → Ni2+
• Chloride is the anionic form of chloride from group 7A → Cl-
• When ions combine, their charges or oxidation numbers crisscross to become subscripts
• Ni2+ will have a subscript of 1 from Cl- → Ni
• Cl- will have a subscript of 2 from Ni2+ → Cl2
• Subscript 1 is no longer indicated → NiCl2
• dihydrate indicates that the nickel chloride has two (‘di) molecules of water of crystallization → NiCl2(s)∙H2O
• Heat has no chemical formula.
• It is used to drive the reaction forward.
• Since the reaction consumes heat to proceed, the reaction is endothermic.
Write a balanced chemical equation for the following and classify the reaction.
Heating solid nickel chloride dihydrate yields solid nickel chloride and water vapor.