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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: cindyy on February 08, 2010, 09:39:31 pm

Title: equations!
Post by: cindyy on February 08, 2010, 09:39:31 pm
the use of cast iron cookware with acidic foods such as fruits can result in significant amounts of iron(II) ions being incoroperated into the diet
a) write a blaenced ioin equation equation showing the formation of iron(II) ions in an acid solution
Title: Re: equations!
Post by: cindyy on February 08, 2010, 09:42:59 pm
oh really? I thought it wuold have to include like an acid :S
Title: Re: equations!
Post by: monokekie on February 08, 2010, 09:44:06 pm
lol, just deleted what i have written, a classic example of me not reading the question properly.

Fe(s) ----> Fe2+ (aq) + 2e-

2H+(aq) + 2e- ---->H2(g)

overall: Fe(s) + 2H+(aq) ------->  H2(g) + Fe2+ (aq)
Title: Re: equations!
Post by: cindyy on February 08, 2010, 09:45:19 pm
Lol okay, thanks so much :)
Title: Re: equations!
Post by: appianway on February 08, 2010, 09:45:43 pm
I think monokeke's equation is a half cell equation...

Another half cell equation would be 2H+ + 2e --> H2 (g)

So combining the two gives 2H+(aq) + Fe (s) --> H2 (g) + Fe2+ (aq)
Title: Re: equations!
Post by: stonecold on February 08, 2010, 09:47:37 pm
i think it is just redox with an acid such as H2SO4.
it says you have to use an acid right?
Title: Re: equations!
Post by: cindyy on February 08, 2010, 09:49:05 pm
i never would have thought of that :S So it is basically a redox reaction. The H+ would be the acid ?
if it was me i would have use like HCl or something. haha thanks guys!
Title: Re: equations!
Post by: monokekie on February 08, 2010, 09:50:47 pm
the use H+ (protons) pretty much indicates the presence of acids :)
Title: Re: equations!
Post by: stonecold on February 08, 2010, 09:51:51 pm
sweet.  :)

nice and simple..yay!
Title: Re: equations!
Post by: cindyy on February 08, 2010, 09:52:34 pm
ooh coolies. (Y) (Y)
Title: Re: equations!
Post by: appianway on February 08, 2010, 09:57:06 pm
Yup. Remember that in ionic equations you only write the ions that are participating in the reaction, and in this case, only the H+ (proton) reacts, and hence it doesn't matter what acid you use, seeing as the other ion's not going to react.
Title: Re: equations!
Post by: monokekie on February 08, 2010, 10:01:40 pm
yeh, good point :)

also remember that only substances that change state(or oxidation number) in a reaction will be included in ionic equations.
Title: Re: equations!
Post by: cindyy on February 09, 2010, 04:39:40 pm
oh okay, i will keep that in mind next time!:)