Destroyer Gchem #130

[DENT2008]

I got in trouble for posting the exact question earlier, but here it goes again- not exactly as written....

when 200mL of .02 M KMnO4 reacts with zinc, how many mg of zinc are needed?


*I'm really confused on how they get .04mols of KMnO4/MnO4, I thought it was .01 mols... Please help, Thanks

 

[bruinguy083]

M=Molarity=moles/liters. in this case, you have .2 liters. .2x.02 should get you .004 mols of kmno4.

how did you come up w/ .01? Hope this helps.

 

[DENT2008]

ok, im seriously an idiot- i divided instead of multiplying... i've been staring at that problem for way too long to even see the obvious.

thanks!!

 

[pre-dentalguy]

ok, im seriously an idiot- i divided instead of multiplying... i've been staring at that problem for way too long to even see the obvious.

thanks!!

Its essential that you get the Molarity understood for the DAT.