okl123 wrote:i put the multimeter on a 9V setting and got answers all around 4.5 range, what do i do
I do not know if what you did here was with the probe 1) immersed in the electrolyte or 2) out in the air. But in neither case should you be seeing 4.5 V.
For case 1) you should see 9V, because the very large resistance of the multimeter when set to measure voltage prevents any significant current from flowing, and therefore the E=IR voltage drop from the resistance of the probe in the electrolyte will be zero, and the entire battery voltage will appear at the terminals of the voltmeter. If this is what you did, then either your battery is dead, or your meter is broken (not just a blown fuse).
For case 2) the probe in air is an "open" circuit, that is no current can flow through the loop at all. This is the same as having the voltmeter measure the voltage of the air, so you should see 0 volts. If you see 4.5 volts then the most likely explanation is that your meter is broken (not just a blown fuse).
WW -- if you read this, can you think of any other explanations for the 4.5 V readings?
In the message before your last post you said
"I am testing water, milk, diet cokem, gatorade, and orange juice and i set the multimeter on the 200mA range. I am getting answers like .1, .5, and .6! Is this rigt? and how to i figure out the electrolyte values from here?"
When you see such small readings on a multimeter it means you should change to a more sensitive setting, such as the 20mA range. However, as I noted above, it's likely that your battery and/or your multimeter is dead.
Getting a new battery should be pretty easy. Be SURE never to short out the battery, either by connecting the wire leads from the battery terminal cap together, or, even worse, putting the multimeter probes across the battery when the meter is is set to measure mA. The first case will quickly drain your battery, leaving it partially or wholly discharged (symptom: the voltage across the terminals will be less than 9 V; this is possibly what might have happened in case 1) above. The second case will blow the fuse on the multimeter; however the fact that you were getting readings of 4.5 V according to your second posting seems to indicate that your fuse has not blown.
Any chance that you can borrow another multimeter?
I am sorry that you are experiencing such frustrating difficulties. Experimentation is, indeed, challenging. I hope you persist and find out where the problem lies. Please keep in touch. Also, remember that even if you do not get the "right" answer, if you write up what you did, and the various steps you took to trouble-shoot the experiment, you may well get a decent grade. In my undergraduate days, I not infrequently attempted to perform lab experiments that had been "packaged" with instructions and equipment and failed to get reasonable results. By reporting my efforts fully and honestly I always got good grades anyways, unlike some of my fellow students who attempted to "fudge" their results to agree with what they thought they "should" be. Honesty is of the greatest importance in science. Tolerance for frustration is a prerequisite for all experimenters.
Best of luck!