Lot's of chemistry homework! D:

Ok, I got a full day’s worth of chemistry homework completed just now, and I was wondering if some of it’s correct. The unit is on displacement reactions, and what can react with what, and the opposite.

There’s 44 questions:

  1. Cu + HCl => No Reaction
  2. Cu + H2O => No Reaction
  3. Cu + FeSO4 => No Reaction
  4. Cu + MgSO4 => No Reaction
  5. Cu + SnCl2 => No Reaction
  6. Mg + HCl => H2 + MgCl
  7. Mg + H2O => H2 + Mg(OH)2
  8. Mg + FeSO4 => Fe + MgSO4
  9. Mg + CuSO4 => Cu + MgSO4
  10. Mg + SnCl => Sn + MgCl
  11. Sn + HCl => H2 + SnCl2
  12. Sn + H2O => No Reaction
  13. Sn + FeSO4 => No Reaction
  14. Sn + MgSO4 => No Reaction
  15. Sn + CuSO4 => Cu + SnSO4
  16. Zn + HCl => H2 + ZnCl2
  17. Zn + H2O => No Reaction
  18. Zn + FeSO4 => Fe + ZnSO4
  19. Zn + MgSO4 => No Reaction
  20. Zn + CuSO4 => Cu + ZnSO4
  21. Zn + SnCl2 => Sn + ZnCl2
  22. Fe + HCl => H2 + FeCl2
  23. Fe + H2O => No Reaction
  24. Fe + CuSO4 => Cu + FeSO4
  25. Fe + MgSO4 => No Reaction
  26. Fe + SnCl2 => Sn + FeCl2

Those I am pretty certain on; but the next questions I am totally unsure of, and also I’m not sure on the formulas, but Fe3C is supposed to be steel, and Fe(Cr4C2)2 is supposed to be stainless steel, and Fe(Zn4C2)2 is supposed to be galvanized steel:

  1. Fe3C + HCl => FeCl2 + H4C
  2. Fe3C + H2O => No Reaction
  3. Fe3C + FeSO4 => No Reaction
  4. Fe3C + MgSO4 => No Reaction
  5. Fe3C + CuSO4 => Cu2C + FeSO4
  6. Fe3C + SnCl2 => Sn2C + FeCl2
  7. Fe(Cr4C2)2 + HCl => No Reaction
  8. Fe(Cr4C2)2 + H2O => No Reaction
  9. Fe(Cr4C2)2 + FeSO4 => No Reaction
  10. Fe(Cr4C2)2 + MgSO4 => No Reaction
  11. Fe(Cr4C2)2 + CuSO4 => Cu(Cr4C2)2 + FeSO4
  12. Fe(Cr4C2)2 + SnCl2 => Sn(Cr4C2)2 + FeCl2
  13. Fe(Zn4C2)2 + HCl => No Reaction
  14. Fe(Zn4C2)2 + H2O => No Reaction
  15. Fe(Zn4C2)2 + FeSO4 => No Reaction
  16. Fe(Zn4C2)2 + MgSO4 => No Reaction
  17. Fe(Zn4C2)2 + CuSO4 => No Reaction
  18. Fe(Zn4C2)2 + SnCl2 => No Reaction

Yeah, if you could check those; that’d be sweet.

There’s no one in your class you can ask? No answers in the back of your text?

I’m the head of my class, I have no one’s phone #, and this isn’t from the text.

Well, I’m sure you’ll get the right answer from the good people here at RPGC, so sit tight (no pressure ha ha ha :P) And that’s me being serious :slight_smile:

27-30 I’m sure are correct. . . 31 and 32 make sense (I’m not sure on these two, but if you think they’re right, I’d go with it). . . 37 and 38 make sense (ditto), but I don’t know about the others.

Hoo boy.

I don’t think anyone will actually verify all the answers, but I’ll tell you the method.

There should be a table (if it’s not in your book, which it should be, then search for it online) stating a few rules about metal reactivity with certain polyatomic ions or non-metals. If you follow those rules you should be able to get most, if not all, of the answers.

It should look something like this:
-------- SO4(2-) ----------- NO3 (-) ----------- ClO3 (2-) ------ etc.
Fe -----always-------------never----------------only with blah--------
Cu -----always--------------always-------------always
Mg------never---------------never--------------never—

It could also be arranged in a list, or flow chart, or something like that though. Search in the chapter that you’re working on.

There’s a chart which shows which cations can replace which cations in displacement reactions, and also for anions. But since there are alloys in the lower questions, I can not tell whether or not they displace hydrogen/cations in the other product.

It’s been a while since I took Chemistry, but I seriously doubt that the answer for that many problems would be “No Reaction.”

For all the questions with No Reaction as the product, means that the first reactant does not “overpower” the cation in the second reactant, therefore making the products the exact same as the reactants.

It’s like saying that Fe + H2O gives out Fe + H2O, not Fe(OH)2 and H2. Although I realize that the second pair is the correct products, I’m just giving an example.

There is a surprisingly large amount of No Reaction in there. Your teacher wouldn’t throw that much unless he was hit on the head with a blunt object – there’s no point.

I can’t tell for the alloy part, but otherwise at least most of the ones with ‘no reaction’ are right.

God damn I hate Chemistry.

Every sane person does. The little chemo I know was either forced upon me by school, or I learned in order to make some toys (like green fire, Devil’s Blood or bubble bombs) in the chemo class.

Only chemistricians like chemistry. And none of them are sane. I was told so by my last chemistry teacher. He said he’d suffered brain damage from smelling some substances so much. He told me which, and they were a lot, but I can only recall benzene, ether and chloroformium now.

And I think that originally there was alchemy, which was invented by humans. It wasn’t fully functional and people pursued a lot of inexisting thingies, but at least things weren’t so unfun. Then Satan saw that the thing had a great potential to annoy the hell out of people and used the concept to create chemistry, then force a gradual worldwide change from alchemy into it.

Conditions for a double reaction to take place are:

  1. Creation of a gas
  2. Creation of a precipitate
  3. Creation of water
  4. Acid/Base neutralization (Creation of water)
    That’s what I remember. I’m a little sketchy on which would create a precipitate, so I’m not going to be able to provide specific help.

Acid/base reactions occur only if the pKa of the acid reactant is much smaller than the pKa of the other reactant, so maybe you have a pKa table in your textbook.

I didn’t take chem.

Thank god.

Chemists. And I like chem. Although I have a preference for organic chemistry, general chemistry is prety neat nevertheless.

Nooooo! I took three semesters of organic and really never liked it. I think that’s partially why I took a job as an analytical chemist. Sometimes I don’t even like that, either, ha ha.

Random question - when exactly did organic chemists stop taste-testing new compounds and washing their hands in benzene? :wink:

When all the stupid ones died.

Natural selection.

Hmm, no. Some students in a local college’s chemo course have a reputation of tasting everything that’s lab made. If you pay them a visit, they’ll probably do somehting like offering you a cup with some transparent, odorless liquid and ask you to taste it, claiming that it tastes like lemmon juice. It’s actually sulphuric acid in low concentration. My teacher was their guest once and experienced this. He confirms the lemmon juice taste. Okay, this one is not a dangerous experiment, but there are worse. One of the students became a living legend known as “the monster” due to the way he behaves now after so many years of tasting experiments. Chemicals ate his brain from inside out.

Those guys are really hardcore. I once saw them using some big contraption to convert ethanol into propanol, buthanol and so on with heavier stuff. The hypothesis was that if methanol could kill instantly with small doses while ethanol killed slowly with big doses, then somewhere before decanol they would possibly find a safe booze. Yes, they intended to test on themselves.