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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: Hailey on April 12, 2007, 06:18:15 PM

Title: Acid Base Reaction
Post by: Hailey on April 12, 2007, 06:18:15 PM

A 1.87 gram sample of Mg reacts with 80mL of a HCl solution whose pH is -.544  What is the pH of the solution after all the Mg has reacted, assume constant volume.

I have no idea how to work this problem.

Title: Re: Acid Base Reaction
Post by: Dan on April 12, 2007, 07:46:31 PM

what's the balanced equation for this reaction?

Title: Re: Acid Base Reaction
Post by: Hailey on April 12, 2007, 09:42:47 PM

That is the problem - I don't know

Title: Re: Acid Base Reaction
Post by: constant thinker on April 12, 2007, 09:46:14 PM

Start with what you have, the reactants.

Mg + HCl --> ?

I'll give you 2 hints as to what the products are.
It's a single replacement reaction.
You will have 2 products.

Title: Re: Acid Base Reaction
Post by: Hailey on April 12, 2007, 10:15:24 PM

I got the single replacement - but, I don't know what to do because I have two molarities on the left side and I don't know how to combine them or whatever to get variables on the right side

Title: Re: Acid Base Reaction
Post by: Borek on April 13, 2007, 02:51:41 AM

Please write your reaction equation. List both molarities you think you have on the left.

Title: Re: Acid Base Reaction
Post by: Hailey on April 13, 2007, 07:44:12 AM

.96Mmg    3.5MHCl

Title: Re: Acid Base Reaction
Post by: Dan on April 13, 2007, 07:53:56 AM

Start with the balanced equation, do not worry about the molarities yet, just get the chemical equation first.

If you don't know that the equation is, you can do a little research online.

eg. http://www.google.co.uk/search?sourceid=navclient&ie=UTF-8&rls=GGLJ,GGLJ:2006-34,GGLJ:en&q=magnesium+acid+reaction

So, what is the balanced equation.