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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: HDW on May 11, 2008, 10:00:05 AM

Title: Reacting Mg with H2SO4 question
Post by: HDW on May 11, 2008, 10:00:05 AM
I'm reacting H2SO4 conc 1.00 and 25 cm3 with excess magnesium in a conical flask.  Is it possible to remove the magnesium and weigh the remaining magnesium?  Is it possible to just remove the MGSO4 and then remove the Magnesium solid afterwards?

thanks for any help.
Title: Re: Reacting Mg with H2SO4 question
Post by: cliverlong on May 12, 2008, 05:23:14 PM
Quote from: HDW on May 11, 2008, 10:00:05 AM
I'm reacting H2SO4 conc 1.00 and 25 cm3 with excess magnesium in a conical flask.  Is it possible to remove the magnesium and weigh the remaining magnesium?  Is it possible to just remove the MGSO4 and then remove the Magnesium solid afterwards?

thanks for any help.
You are along the right lines.

What do you know about MgSO4 in this particular situation? How would you remove it? Look at the equation for this reaction where there are state symbols ( solid, liquid, gas, aqueous) for all reactants and products.

Why do you think the question states an excess of Magnesium?


Clive
Title: Re: Reacting Mg with H2SO4 question
Post by: virus_freak on May 23, 2008, 03:49:12 PM
If there's excess Mg then you could use filtration.
However to get the Mg out of the MgSo4 soln' youll have to react MgSo4 with K or Ca and weigh the Mg collected the equation is this:

2K(s) + MgSo4(aq) = K2So4(aq) + Mg(s)

A displacement reaction would occur and you can get back your original Mg which was used in the first place.

P.S= The reason they used excess Mg is to make sure that all the H+ ions have been liberated from the H2So4 acid especially because it was concentrated.
Title: Re: Reacting Mg with H2SO4 question
Post by: Borek on May 23, 2008, 04:02:49 PM
Quote from: virus_freak on May 23, 2008, 03:49:12 PM
2K(s) + MgSo4(aq) = K2So4(aq) + Mg(s)

Have it occured to you that K will react with water and not with Mg2+?