TokenMonkey

What is the point then?

I know the answer to this, but considering this was posted a while ago, I don't know if you still need the help. If you do, just shout.

I've been thinking about supposed IQ tests that are used to test "intelligence". What do they really test? My point is this: intelligence, as I see it, is the ability to solve a problem in an unknown situation using the tools and knowledge one has. IQ tests have all these questions which, to a large extent, are composed of maths (or math for the Americans) and language questions. But these things are a matter of education. One can be taught to do well in an IQ test. But what if someone off the street, who has had no education, takes an IQ test, and can't answer 2+2, merely because he or she has never been taught maths. That person's results would be awful, and they would be seen as having a low IQ. However, that doesn't mean that that person is incapable of solving a problem with the tools that they have. It's just that they don't have the means of solving those particular problems. What do you guys think about this? Is there any way to really test someone's intelligence?

Aaarrrgh! Please! Someone's gotta know about this stuff!

Nope. I've thought about it, but I can't seem to find a solution. Then again, I'm only good at maths, I'm not a genius at it.

That's what I was thinking but then isn't it a waste if the ions in the salt bridge run out before the anode is eaten away? The other thing I was thinking is this: Why do you even need a solution in the salt bridge. Here's my reasoning, and I'd love it if someone could explain why it's wrong: At the anode, the following reaction occurs: Cu -> Cu2+ + 2e-. The electrons flow to the cathode through the wire. That's all fine. At the cathode: Ag+ + e- -> Ag. That basically means that the anode has an overall positive charge (excess of Cu2+ ions) and the cathode becomes negatively charged (excess of NO3- ions). Couldn't the Cu2+ ions just flow through the U-tube to neutralise the negative charge, and NO3- goes to neutralise the positive charge. But this then also means that the electrons themselves could flow through the water and not through the wire. So obviously the solution in the salt bridge separates the two half-cells. But why? How?

My final chemistry exam is in about a week, and I still don't know EXACTLY how salt bridges of electrochemical cells work. None of my three textbooks explain it in-depth. I know the salt bridge's functions, but what exactly happens? For example, let's say we have a Cu anode and Ag cathode, in their respective half-cells. The electrolytes are Cu(NO3)2 and AgNO3, respectively, in the half cells. Let's say there's MgSO4 in the salt bridge. I understand that without the salt bridge, the half cells would become charged and the electrons wouldn't flow. That's all fine. What I don't get is which ions go from where to where to maintain the overall neutrality of the cell.