ATAR Notes: Forum
VCE Stuff => VCE Science => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Chemistry => Topic started by: merlin on September 18, 2008, 08:13:54 am
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I need help with q.14 of the multi choice in the 2008 sample chem exam. I'm sure B, C and D are all incorrect, however for me A doesn't make sense, cause I thought anions will flow to the postive electrode and cations will flow towards the negative electrode. Anyway, can anyone explain? :o
(http://www.vcaa.vic.edu.au/vce/studies/chemistry/2008chem2-samp.pdf)
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cause I thought anions will flow to the postive electrode and cations will flow towards the negative electrode. Anyway, can anyone explain? :o
Wrong. In a galvanic cell, the salt bridge is required so that negative ions can replace the loss of negative charge (electrons) from the anode (where you lose electrons) and also so that positive ions counter-act the build up of electrons at the cathode (where you gain electrons).
Hence, anions flow to the anode and cations flow to the cathode (in galvanic cells - discharging).
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O I c, thanks! I think I was getting mixed up with electrolytic cells!
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Yeah, the question was trying to be a bit tricky. There's no difference between the operation of a secondary and primary cell, when they're both discharging. They only differ by the fact that secondary cells are capable of recharging, but the question was saying "for their discharging process," nullifying any differences between them.