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VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: Comatose on October 09, 2011, 12:50:20 pm

Title: help with balancing half equations
Post by: Comatose on October 09, 2011, 12:50:20 pm

hey guys just few questions with chemistry
iive shown my working with the book answer too.
can someone show me where im going wrong? cheers

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Title: Re: help with balancing half equations
Post by: REBORN on October 09, 2011, 12:51:11 pm

Cancel out your H+'s on both sides.

Title: Re: help with balancing half equations
Post by: Comatose on October 09, 2011, 12:58:16 pm

why do we cancel out the H+'s? it says cancel out the electrons OH RIGHT H+ is an electron yeah?
that explains q1. but what about q2?

Title: Re: help with balancing half equations
Post by: REBORN on October 09, 2011, 01:00:02 pm

No...

H+ is a proton.

You have ...... + 8H+ ..... ----> ...... + 6H+

This is equivalent to having 2H+ on the left hand side.

Title: Re: help with balancing half equations
Post by: Russ on October 09, 2011, 01:00:29 pm

You can cancel H+ out when it's on both sides for reasons that aren't particularly important. Think of it like balancing a maths equation. H+ is also definitely not an electron (it has none, it's just a proton)

Title: Re: help with balancing half equations
Post by: jasoN- on October 09, 2011, 01:06:28 pm

1. H+ isn't an electron, it's a proton
But since there's H+ on either side of the equation you can cancel it out (works for any other molecule too)

2. Charge on LHS: +12. Charge on RHS: +6
Hence you need to add 6 electrons on the LHS.

Title: Re: help with balancing half equations
Post by: Comatose on October 09, 2011, 01:06:48 pm

awkward my bad haha
thanks alot guys