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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: daneosaurus on March 22, 2010, 12:54:03 AM

Title: Predicting the products of a reaction
Post by: daneosaurus on March 22, 2010, 12:54:03 AM

I've seen a couple posts about this kind of stuff with answers, but I've never heard an explanation of why. With these reactions:

Mg(s) + H₂O  :rarrow: MgO + H₂

and

2Na(s) + 2H₂O  :rarrow: 2NaOH + H₂

How do you know whether an oxide or hydroxide product will be formed? I understand alkali and alkali earth metal reactions with water liberate hydrogen gas, however it doesn't seem obvious to me that magnesium oxide would form instead of magnesium hydroxide. What is the determining factor?

Title: Re: Predicting the products of a reaction
Post by: Wald_ron on March 27, 2010, 09:37:31 PM

Are you sure that those equations are correct?

Title: Re: Predicting the products of a reaction
Post by: Grundalizer on March 28, 2010, 07:18:04 PM

I agree with the sodium equation, I disagree with the Magnesium reaction.

Magnesium reacts with water to form hydrogen gas and magnesium hydroxide.

Mg (s) + 2 H2O (l) → Mg(OH)2 (s) + H2 (g)

Was your source of those equations a person, book, or other internet place?