chemistry

I'm no expert on this, however I do have a suggestion for you to consider. With the first set of reagents the phenacetin undergoes a base-catalyzed haloform reaction which cleaves off the methyl group. Now with the second set it may be that the acetic acid is used to oxidate the carbonyl carbon and subsequently undergoes a nucleophilic addition (and elimination?) reaction with the urea. Especially this second aspect is a bit fuzzy and I'll get back to you later on it.

As I said and explained the value of the e- is not insignificant. How could you learn chemistry without realizing the significance of oxidation states; Fe is not the same as Fe(III). Despite the plausible existence of teachers who are ignorant enough to underemphasize this point, this subtle detail should be pointed out...as I have done. And I'm sure you would agree by now that pointing out this aspect of the problem was not in error, certainly not stupid.

The fact is that this problem also deals with knowledge of oxidation states and the periodic table. So it is significant for any grade level. As I said, the mass of the electron, if associated with a high mole value, will be very significant to the problem and will result in deviations from the real value. If your perspective is that of a step by step process in learning this material...I somewhat understand you. However, my opinion as well as all teachers, I am sure will require that the student understand the subtle aspect of this problem mainly since it deals with contents of other chapters.

The periodic table refers to atoms with 1:1 ratio of electrons to protons. Especially when we are dealing with high mole values this error will lead to a significant deviation from the true value. And yes, it is General Chemistry even high school chemistry where professors will use subtle problems as this to mark off the A students from the B...and thus your ignorance in chemistry.

It is inappropriate to use the molar mass of Fe on the periodic table when it asks for Fe(III) which has lost three electrons. -------------- Online help with college and high school chemistry

What we are concerned about is regarding the equilibrium temperature (in relevance to an closed system and q=ms(dT)) upon adding ice; we don't wish it to reach anywhere near the freezing point of ammonia (assuming ammonia constituted a much larger portion). I would imagine that in most cases ice would dissolve in ammonia and that the reaction in most cases would be slightly exothermic...hydrogen bonds can be formed in the solution and the entropy change would probably be positive.

You have the total mass of the solution. You also have the specific heat...use q=ms(dT)

Number 2 was unsolved. I guess I should have attempted this problem only.

From Ka, find Kb, find pOH then find pH. The key here is that the reactant is a solid and thus it is not incorporated in to Kp; in Kp=p of products only. You should know how to do it now. Be sure to pay attention to exponents. Use the henderson-hasselbach equation. The hydroxide anion reacts with acetic acid thus decreasing its concentration relative to the base; this is the only significant change. Thus account for the decreased concentration of acetic acid. Not sure what is meant by the last statement. If it means what I think it means: you know the concentration of hydronium ions in pure water [H+]. Thus pH=-log[H+ of water + H+ of the acid]. Solve for the latter. You should know the rest.

Well, think about it. Lowest unoccupied molecular orbital with another unoccupied molecular orbital, no covalent bonding can take place.

It's the first one. Look at the rate law to determine which equation stands for the rate determining step.

Try looking up HCN. Reactions with CN anion and a acidic substance is performed within a ventilated hood.

In almost all cases no. Reactions contribute to a change in entropy.

Use PBR3 to convert the alcohol to an akyl halide. Use a moderately strong base to deprotonate the central activated hydrogen (methylene). You don't want the base to react with either of the carbonyl groups. The alkyl halide and the resonance stabilized enolate compound (the deprotonated dicarbonyl compound) will react by SN2 reaction and you will have your product.

Salts can be formed from the reaction of an arrehnius acid and a arrenius base. The properties of this salt in aqueous solutions reflect the strength of each acid and base.

They are about the same in pH (meausure of intrinsic arrehnius acid strength)

It's due to effective nuclear charge and the also its small size.

The oxygen in the peroxide has a different oxidation number (it's not -2). Try figuring it out for yourself

There are plenty of better oxidizing agents. Its just that with nitrates the reaction is more "controlled" instead of spontaneous. And thus its use with gunpowders and such.

Protons, by itself would be in a gaseous state, just heat hydrogen atoms to a high temperature. Acidity, most commonly pertains to reactions in aqueous solutions and thus the above does not apply. In water acidity is maintained by the presence of a strong acid, and its weak conjugate base. HF is an exception to the acid trend of its group since its bond dissociation energy outweighs its characteristic as an acid due to its polarity.

Notice that carbon is more electronegative than any other elements with the same valence electron number (4 electrons). Thus carbon easily forms tetrahedral arrangements and more importantly it can form extended networks with other carbons.

Note that water may also act as an insulator. Particularly when it freezes. The temperature between the water and the grapevine is not too different at first, due to the specific heat capacity as you mentioned water takes a long time for it to have lost the all of the heat energy, especially to air. ------------------------------------------------------------------------------------ Online Chemistry Help http://groups.msn.com/GeneralChemistryHomework

pKD...never heard of it. pKa or pKb I can understand. If you had just made a typing error and pKD=pKa for example then... Add water to 121g of the substance then add water until it reaches 1 L. Find a buffer system with a pH of 7 and/or use the Henderson-Hasselbach equation or neutralize the substance with the proper acid or base. The latter will probably be easier. ------------------------------------------------------------------------------------ Online Chemistry Help http://groups.msn.com/GeneralChemistryHomework

"why is aluminum sectible? is it the electron structure?" By sectible I think you mean relatively "soft" compared to other metals. The hardness of a metal depends on the delocalization of its electrons. And this has to do with molecular orbitals in relation to valence band and conduction band. If you still are not able to figure it out tell me. Crystal is rather a vague term. I think what you two are disputing about is the difference between a long range covalent network and an ionic compound. Both have an organized structure; e.g. closed packed structure etc...A long range covalent network can apply to pure covalent compounds as well as a molecular network. ------------------------------------------------------------------------------------ Online Chemistry Help http://groups.msn.com/GeneralChemistryHomework

Notice that the grapevine will decrease in temperature. Water covering the grapevine will be in direct contact with it and more heat will thus be transferred through this route then through transfer to air. This is why when you wish to cool a substance more effectively you place it in water rather then expose to air of the same temperature. Hope this helps. ------------------------------------------------------------------------------------ Online Chemistry Help http://groups.msn.com/GeneralChemistryHomework