fterh

Yeah I get what you mean Sort of.

I understand that connecting identical batteries in parallel will increase the overall battery's capacity. But what about: 1) If the batteries aren't identical? Say one is 2V, and the other is 4V. What will happen? Is there an equation to calculate overall emf? 2) If the batteries do not have negligible internal resistance? That is to say, e.g. each battery have internal resistance of 1 ohm. If you connect two of them (identical) in parallel, the overall resistance of the battery will become 0.5 ohm. So does the current in the circuit increase due to decreased overall resistance?

Found this question online: A ball with a mass of 250 g has a centripetal acceleration of 5 m/s2. What is the centripetal force acting on this ball? My calculation is 0.25 * 5 = 1.25N, but the answer is 1250N. I think the answer is wrong (because I believe all calculations should be done in SI units), but I just want to verify. I'd appreciate if you guys use simpler terms, because I'm in secondary 4 (high school equivalent) and this stuff is beyond my level (it's for Physics Olympiad). Thanks!

Nah it isn't homework It's further revision for my upcoming test on organic chemistry Anyway to answer your questions: 1) hydroxyl, -OH 2) nope, one isn't provided anyway 3) anol But cholesterol doesn't have the "anol" appended to it. Merged post follows: Consecutive posts merged I think I get it, thanks! :D:D

1) Cholesterol is an organic molecule that occurs in the blood stream. What type of compound is cholesterol? A) an acid B) an alcohol C) an alkane D) an alkene I guessed A because cholesterol comes from fats which are fatty acids. But the answer is B Why is that? 2) A compound known in industry as "MTBE" is used as an additive in lead-free petrol. The structural formula of MTBE is shown. Why isn't this the answer? P/S: I know this belongs in the Organic Chemistry sub-forum, but it's really dead in there and I hope to get my answers ASAP :-)

Thanks for the answers And pertaining to the propane (C2H6), my bad, meant to type (C3H8)

I understand that cracking is defined as the breaking down of large hydrocarbons into smaller ones, whereas dehydrogenation is the removal of hydrogen atoms If propane were to be broken down into propene (C2H6 to C2H4), is that cracking or dehydrogenation, or both? And I have a question that asks about cracking, in the diagram it shows liquid alkane on mineral fiber heated in a test tube with aluminum oxide. May I ask what is the aluminum oxide used for?