Electrolyte Challenge- PLEASE HELP ASAP!

[scienceluver7]

Hey(:

Kayy I need help reallllly badly. So I am doing the Electrolyte Challenge: Orange Juice vs Sports Drink, but I changed up the liquids to different ones. Kay the REAL problem: the circuit and the current. I checked everything, the battery is still charged, the copper wire is working fine, the bettery clips are definitly working, and the multimeter probes are working fine. But when we dipped it into a sports drink (Gatorade), no current flowed! I am sooo frustrated with this project and I really need help asap. The Gatorade is fine, we just bought it yesterday, so it is still fresh (i guess). It is at room temperature, as instructed. The instructions are driving me CRAZY! They were just so confusing. I might have missed on a few details, so please tell me what is wrong! Oh, and my conductor is a plastic straw. Is that okay? I am sooo frustrated and my project is due soo soonn! PLEASE REPLY ASAP! Thank you!

[deleted-93346]

Sounds like you are having a hard time. I can sympathize -- I've had stuff I put together for the first time refuse to work many, many times. Experimental science is hard: whatever can go wrong, will go wrong. But don’t panic. I guarantee that the problem can be found and fixed. You will need to be patient, however. Now I don’t
have your stuff sitting in front of me, which makes it hard for me to do too much. But let’s try a few things to see if we can narrow down the places where the problem may be hiding.

1. double check that A) the multimeter is ON, B) the selector switch is set to the most sensitive current scale (I don’t know what kind of multimeter you are using, but the current settings will read in either milliamps or microamps; you want microamps if available and the smallest number, maybe 2000 microamps full-scale), and C) that the two leads are plugged in to the correct holes on the multimeter (there will be one black hole labelled something like “common” and two or more red marked holes: you must use one that has a label that includes “ma” or ‘mA”, this label may also include “mV” and/or “ohm”)

2. that was probably OK, right? So now we need to check the multimeter, wires, and battery. To do this, disconnect the two alligator clips that connect to the conductance probe. Then switch the multimeter to read DC Volts on a scale that can read 10 volts, possibly a 20 V scale. Check that the red hole you are using also has the label “V” — I think it will, but if it doesn’t you’ll need to plug the red lead into the hole that does have that label. Now clip the two alligator clips that you detached from the conductance probe together. If all is well the multimeter should now read a little over 9 volts, since what you are connected to in this set up is just the battery. If the multimeter reads zero, then you have succeeded in isolating the problem to the multimeter, the leads, and/or the battery. If the multimeter reads about 9 volts, all those parts of our setup are OK, and the problem is in your conductance probe and/or your electrolyte solution.

3. Once you know which is the case, take a good, hard look at the offending parts and see if you can spot something visibly wrong. If you can’t see anything, then you will need to devise ways to isolate the problem further. For example, suppose in part 2 above you determined that the multimeter, leads, and battery are OK. Then you could reconnect the apparatus in the normal fashion, check that it still does not work (I don’t know why, but sometimes just checking things can mysteriously fix them!). Now you need to substitute something for your probe. If you have some insulated wire, you could take two pieces and tie them into a knot with a short and long end of each wire sticking out. Then strip off enough insulation on the long ends that you can attach the alligator clips to them. On the short ends, strip back an inch or two of insulation, allowing the natural stiffness of the wires to keep them from shorting out against each other, but as close to each other as possible — some scotch tape may help to mechanically stabilize this “kluge”. After verifying that no current flows when this makeshift probe is dry, put it in your electrolyte. Do you get a little current? If so, then your first probe has something wrong in it. If you don’t get any current, try a better electrolyte, such as vinegar or salt water. (To make salt water stir as much salt as will dissolve into hot water from the hot tap in your kitchen, stirring vigorously for a minute or so. Don’t scald yourself on the hot water!). Still nothing? Your multimeter may be partly broken…

Anyway, the debugging tree branches too much for me to go further. If you reach a dead end, write back and someone can suggest further steps to locate and fix the problem.

Best of luck. As the saying goes, “genius is 1% inspiration, 99% perspiration…”

[scienceluver7]

THANKS SOO MUCH(: After i read this, I also read a few other questions and answers and one of them specified the wiring of the circuit! I appreciate your help!

[deleted-90338]

I think I saw a kid doing this kind of experiment in class one time, except it was with an orange, not orange juice. Nice project!^_^!

[scienceluver7]

NanoNanoPudding- thankss(: it is reallly cool! and btw loveee your usernamee(: