Text book question 2A.23 (c)

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In the textbook question 2A.23 (c), we are asked to give the chemical formula for aluminum hydride. The answer is AlH3, but I was wondering why H+ can be H- in this case, since the aluminum ion is Al3+.

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Hi,

The question asks about aluminum hydrIDE. Hydride ions are H- rather than H+. When we learn more about nomenclature, I am sure this will make more sense, but for now I have just memorized that when I see the "ide" after hydrogen, it indicates a negative charge. And in this case, hydrogen needs to be negative to cancel out the positive charge of aluminum to produce an overall neutral compound.

Hope this helps,
Quinn