Posted: 4/10/2007 1:10:13 PM EDT
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Help me out here: 1 When a solution of AgC2H3O2 is mixed with NaI, a yellow precipitate is formed. Write a balanced equation (including states of matter) correctly identifying the product, including its correct systematic name. 2 When an unknown solution was added to a solution of Ca(NO3)2, a white precipitate was formed. When HCL was added, the precipitate redissolved without foaming. Write balanced equations for both reactions and correctly name the precipitate and in question 1. (that last sentence doesn't make sense) |
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1. Double decomposition reaction. No real balancing is appropriate because Ag is +1, C2H302 is -1, Na is +1, I is -1. It balances out evenly. AgC2H3O2(solution) + NaI(solution) --------> NaC2H302 (liquid Sodium Acetate) + AgI(solid Silver Iodide) I think I'm right on this as far as the states of matter. The balanced equation is right however. 2.  I just don't get it, I haven't taken chemistry is a while.I hope this makes sense. |
| C'mon, somebody's gotta be able to help me out here. Right now I'm trying to figure out the delta H for three problems to determine the delta H of a fourth problem, and I can't get a single usable figure for ANY of them. One of you guys has to be able to help me with the problems I posted. |
The unknown could be something as simple as NaOH. 2NaOH + Ca(NO3)2 -> 2Na(NO3) + Ca(OH)2 HCl + NaOH + Ca(NO3)2 -> NaCl + H2O + Ca(NO3)2 I don't think Calcium Hydroxide is very soluble. |
But that wouldn't work, as adding HCl to Ca(OH)2 would definitely foam (and spit, and boil). My guess would be NaCl. CaCl2 is insoluble at alkaline pH, I think. So you would get 2NaCl + Ca(NO3)2 ----> 2Na(NO3) + CaCl2 (ppt). HCl would lower the pH and allow the CaCl2 to dissociate. Old-School Geek Humor: What's Mork from Ork's favorite compound? A: Na(NO3), or NaNOOO. Okay, you have to be a geek from the late 70's to get that one.
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Dissociate into what? HCl + CaCl2 + 2Na(NO3) ----> ? Johnny was a chemist's son, But Johnny is no more; What Johnny thought was H20 Was H2SO4. |
I do biology, not inorganics, so forgive my ignorance. Why would the HCl + Ca(OH)2 reaction foam and boil? Is the reaction strongly exothermic? If that is the case, could the reactants be diluted enough to dissipate the heat, but still allow a precipitate to form? |
Tolip, ignore his post. You were correct. |
If I'm right, then there would be no precipitate, as all products would be water-soluble and free ions. So you'd get HCl + CaCl2 + 2Na(NO3) ---> H+ + Ca+2 + 2Na+ + 3Cl- + 2NO3- That's if I'm right, though. |
How? Calcium hydroxide is a strong base; Hydrochloric acid is a strong acid. In general, mixing a strong base with a strong acid will create a strongly exothermic reaction. Unless there's some special properties about Ca(OH)2 that I'm not aware of. |
You're supposed to be adding the HCL to the products, not the reactants. |
2HCl + Na(NO3) + Ca(OH)2 -> CaCl2 + 2H2O + Na(NO3) or maybe 2HCl + 2Na(NO3) + Ca(OH)2 -> Ca(NO3)2 + 2H2O + 2NaCl Check the electronegativities. |
It may get warm, but I doubt it'll run a turbine. Mix some 12M HCl and concentrated NaOH. I'll bet you $10 it doesn't explode. |
No thanks. It might not explode, but I'd bet you'd get a pretty strong reaction. Admittedly, I've never tried it, simply because it's not a very good idea. Have you any experience with it?  Your equation might be correct if you use dilute solutions, though. I don't remember if Ca(OH)2 is insoluble. I do know that it's not a carbonate, because foaming in the presence of an acid is a dead giveaway for a carbonate solution (liberates CO2). Swindle, you'll have to give us the answer when you find it out. I'm very curious as to what it is now. |
Like Tolip said, it will get warm but not boil over. I have a degree in chemistry. It wouldn't be difficult to figure out how much the solution would warm up, but we'd need to know the concentrations of the reactants, starting temperature of the solutions, etc. It sounds like the question is more descriptive rather than dealing with actual mole amounts, etc. |