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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: CandyApples on October 20, 2009, 02:09:28 AM

Title: Reaction Spontanaity
Post by: CandyApples on October 20, 2009, 02:09:28 AM

The question asks if BaCl2 + H2SO4 is a spontaneous reaction, and what does that tell you about delta g. My prediction is that delta G is positive, hence the reaction is not spontaneous. My logic is that one of the products is 2HCl, which has a pka of -7 while H2SO4 is only -3. Since the disassociation favors HCl, it is more likely that the reactants will not go forward with the reaction, hence delta g is positive. Is this the case, or is my logic mistaken?

Title: Re: Reaction Spontanaity
Post by: Borek on October 20, 2009, 02:45:35 AM

Why do you ignore other products?

Title: Re: Reaction Spontanaity
Post by: CandyApples on October 20, 2009, 02:54:42 AM

Well, BaCl2 is soluble in water, and BaSO4 can precipitate out. I guess I just looked at the high instability of HCl and incorrectly made an assumption.