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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: hoggsie on September 29, 2006, 01:27:54 AM

Title: Writing balanced net equations!
Post by: hoggsie on September 29, 2006, 01:27:54 AM

Hi, I have no idea what balanced net equations mean, let alone write them.

a.   An aqueous solution of bromine is added to copper metal, producing copper(II) ions and bromide ions

           Bromine aqueous is Br-, isn't that the same as bromide ions??

b.   An aqueous solution of iron(III) chloride is reacted with aqueous potassium iodide to form iodine; assume that the iodine dissolves in the solution
Not sure how to balance etc.

c.   Hydrogen sulfide gas is bubbled into iron(III) chloride solution, producing iron(II) ions and a colloidal suspension of sulfur

Title: Re: Writing balanced net equations!
Post by: mike on September 29, 2006, 01:39:01 AM

a) bromine Br₂, copper Cu, copper(ii) Cu²⁺ bromide Br^-

b) iron(iii) chloride FeCl₃ potassium iodide KI, iodine I₂

c) hydrogen sulfide H₂S iron(iii) chloride FeCl₃ iron(ii) Fe²⁺

Title: Re: Writing balanced net equations!
Post by: hoggsie on September 29, 2006, 04:13:37 AM

Br2(l) + Cu(s) ? Cu2+(aq) + 2Br (aq)
2FeCl3 + 6KI ? 3I2 + 6KCl + Fe3+

Title: Re: Writing balanced net equations!
Post by: hoggsie on September 29, 2006, 04:58:20 AM

Acidified KMnO4 is added to NaClO3 solution, producing Mn2+ ions and ClO4- ions in solution

KMnO4 + NaClO3 ? Mn2+ + ClO4- + ? What else?

An aqueous solution of iron(II) ions is oxidised to iron(III) by an acidified solution of dichromate ions, Cr2O72-

Fe2+ + Cr2O72- ? Fe3+ +

Zinc is added to nitric acid to produce Zn2+ ions and nitrous oxide, N2O (laughing gas)
Zn + 2HNO3 ? Zn2+ + N2O + H2O

Title: Re: Writing balanced net equations!
Post by: jennielynn_1980 on September 29, 2006, 11:06:43 AM

Steps to writing a balanced ionic equation:

1. write a balanced equation
2. ionize all aqueous substances (not gases or precipitates)
3. Eliminate ions common to both sides of the equation
4. check for the balance of atoms
5. check for balance of charges

If you don't know how to balance an equation at all here is a great website with a great tutorial:
http://www.wfu.edu/~ylwong/balanceeq/balanceq.html

Hope this helps :)

Title: Re: Writing balanced net equations!
Post by: Borek on September 29, 2006, 11:53:02 AM

http://www.chembuddy.com/?left=balancing-stoichiometry&right=balancing-reactions