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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: Xeoning1 on March 04, 2006, 03:21:22 PM

Title: Single Replacement Reaction, Zinc Nitrate and Magnesium
Post by: Xeoning1 on March 04, 2006, 03:21:22 PM
Hi there, Why does Zinc Nitrate (aqueous) not react with Magnesium (solid) ?? I know it has something to do with the activity series but I cant exactly figure it out.


Help would be awesome, thanks :D
Title: Magnesium and Zinc Nitrate
Post by: Xeoning1 on March 04, 2006, 04:21:30 PM
Why does Zinc Nitrate (aqueous) not react with Magnesium (solid) ?? I know it has something to do with the activity series but I cant exactly figure it out. I tried this in an experiment. I believe it has to do with Magnesium Oxide that forms ontop of the Magnesium that doesnt allow the single replacement reaction to occur. any help would be awesome to explain this or help me further understand
Title: Re:Single Replacement Reaction, Zinc Nitrate and Magnesium
Post by: crazybouttennis on March 04, 2006, 10:23:16 PM
I'm not positive, but I think magnesium would react with zinc nitrate to form magnesium nitrate and zinc because magnesium is higher on the activity series of elements than zinc so magnesium should be able to react with zinc nitrate.
Title: Re:Magnesium and Zinc Nitrate
Post by: Albert on March 05, 2006, 05:27:38 AM
I believe it has to do with Magnesium Oxide that forms ontop of the Magnesium that doesnt allow the single replacement reaction to occur.

I think it's magnesium hydroxide rather than oxide.
Title: Re:Single Replacement Reaction, Zinc Nitrate and Magnesium
Post by: Xeoning on March 06, 2006, 08:07:37 PM
Yes You are correct  but when Magnesium is exposed to air it forms MgO (Magnesium Oxide) I Believe this plus its relativity to Zinc on the acticity series helps to explain why it doesnt react. Any more light shed on this would be great
Title: Re:Magnesium and Zinc Nitrate
Post by: Xeoning on March 06, 2006, 08:09:27 PM
Nonono. When Magnesium pure magnesium is exposed to air it forms MgO, it oxidizes readily in air. If a small peice of Magnesium ribbon is placed in Zinc Nitrate, I think this is what stops the single placement reaction from occuring, and it makes it into a double replacement which cannot be completed. Not sure though.
Title: Re:Single Replacement Reaction, Zinc Nitrate and Magnesium
Post by: AWK on March 07, 2006, 01:10:58 AM
Magnesium , even with water, reacts only after warming to boil. I think this will be work also in this case, but this reaction may be more complex.. In this case zinc can react with water or nitrates.