Chemistry - May 2007

please post your answer with the mass number followed by the symbol of the element, followed by any charge on the ion (for example: 19F0, 30P-3, or 23 Na1)

2007-05-19 16:19:41 · 4 answers · asked by s game 1

Must be 100% water poof. No rust or corrosion. I heard stainless steel or aluminum were good. What would be the best for electricity flowing into water (electrolysis)

2007-05-19 16:18:14 · 7 answers · asked by Anonymous

..covalent bond between B-atom and F¯ ion,B atom in BF4¯becomes sp3 hybridized.But this change in state of hybridization of central atom does not take place in case of formation of NH4+ and H3O+ from NH3 and H2O resp. In NH3 and H2O,N-atom and O-atom are sp3 hybridized and the single lone pair in case of the former and the two lone pairs in case of the latter are placed in the sp3 hybrid orbitals which are not involved in the bond formation.On the overlap of such orbital,containing lone pair electrons,in NH3 and one of the two such in H2O,by the empty 1s orbital of H+,NH4+ and H3O+ are formed resp. But in both NH4+ and H3O+,the state of hybridization of N and O remains sp3.So how can I show the formation of BF4¯(ie how to show a vacant 2p orbital of B,perpendicular to the plane of three sp2 hybrid orbitals in BF3,turning to a sp3 hybrid one in BF4¯.). So please explain the change of hybridized state in formation of BF4¯ from BF3..Also suggest a site showing the orbital overlap diagram.

2007-05-19 16:02:33 · 2 answers · asked by Anonymous

Reacting 40mL of 0.200 M AgNO3 with 40mL of 0.200 M K2CrO4 results in what mass of solid form? Pls help. I totally don't get this!!

2007-05-19 12:17:52 · 2 answers · asked by Miami_Tennis 2

I've narrowed down my mystery chemical in my chem lab to these two things (to a good degree of certainty). How can I confirm or deny either one of them?

2007-05-19 12:05:58 · 3 answers · asked by Moodrets 2

then what is the formula for potassium oxide?

and no stupid harsh comments,or you will be reported.I don't need ppl bothering of what I ask on yahoo answers

2007-05-19 11:45:29 · 1 answers · asked by Anonymous

1) A 0.0106L sample of sulfuric acid from an automobile battery requires 0.0348L of 1.95 M sodium hydroxide solution for complete neutralization. What is the molarity of the sulfuric acid? The reaction is shown below.

H2SO4(aq) + 2 NaOH(aq)--->2 H2O(l) + Na2SO4(aq)


2) Calculate the sodium ion concentration when 0.060L of 9.0M sodium carbonate is added to 0.030L of 1.0M sodium bicarbonate.
3) A 0.230L sample of a 0.255M CaCl2 solution is left on a hot plate overnight. The following morning, the solution is 1.10M. What volume of water ( in mL) evaporated from the 0.255M CaCl2 solution
4) Two tuning forks with frequencies of 256 Hz and 512 Hz are struck. Which of the sounds will move faster through the air?
5) What is the resultant displacement at a position where destructive interference is complete?
6) As a result of a distant explosion, an observer first senses a ground tremor, then hears the explosion. What accounts for this time lag?

2007-05-19 11:10:11 · 2 answers · asked by Getmeoutofhighschool 2

A 10.0 mL sample of vinegar, which is an aqueous solution of acetic acid, CH3COOH, requires 16.9 mL of 0.500 M NaOH to reach the endpoint in a titration. What is the molarity of the acetic acid solution?

CH3COOH(aq) + NaOH(aq) → CH3COONa(aq) + H2O(l)

I understand how to do this type of problem; however, the "endpoint in a titration" is a bit confusing to me. Some help please. It would be great if you can provide the answer, so I can double check to make sure I am doing the problem correct. Thank you!

2007-05-19 10:38:46 · 5 answers · asked by christopher239938 1

2007-05-19 10:19:47 · 2 answers · asked by jcorroon 1

there always has to be a why.....

2007-05-19 09:57:04 · 5 answers · asked by Zaneta 1

Use a typical glass size structure for area of effect.

2007-05-19 09:43:47 · 1 answers · asked by Brent S 1

2007-05-19 09:40:24 · 1 answers · asked by Anonymous

2007-05-19 09:28:25 · 1 answers · asked by Soni 2

I once heard that there is a temperature just below freezing where water is niether a solid or a liquid. Is this true? If it is, do you know what that temperature is?

2007-05-19 09:26:37 · 4 answers · asked by Anthony62490 2

64% yield of 1,1 - diphenylethanol and a 16% yield of biphenyl is isolated from the complete reaction of 1.70g of acetophenone. How to calculate the masses of the two products isolated? Why is there biphenyl? Thanks!

2007-05-19 09:26:17 · 1 answers · asked by endlicherii 1

2007-05-19 09:20:23 · 1 answers · asked by judyysan@sbcglobal.net 1

For example laws of preessure i only have gays law charles law and boyles law does anyone have any other laws they can tell me about also can you tell me about any websites

2007-05-19 09:19:00 · 2 answers · asked by cristian_correa@sbcglobal.net 2

in a dissolving reaction:

ammonium chloride + water = ???

is it ammonium chloride solution?
(no formulae needed)

2007-05-19 09:06:05 · 7 answers · asked by no-one listens... 2

Fat + H2O Immiscible

Fat + alcohol Miscible

Fat + vegetable oil Miscible





NaCl + vegetable oil Immiscible

NaHCO3 + H2O Miscible

NaHCO3 + alcohol Immiscible

NaHCO3 + vegetable oil Immiscible

can anyone explan all of these obsrvations in term of bonding and polarity

2007-05-19 08:57:08 · 1 answers · asked by Anonymous

2007-05-19 08:01:01 · 3 answers · asked by summerchem 1

Bronze is an alloy of tin (MM 118.7) and copper (MM 63.55). If a 105.0 gram block of a bronze alloy has a heat capacity of 28.4 J/K, calculate the mole fraction of copper in the alloy. The Dulong-Petit constant = 24.94 J/K.mol. Enter your answer as a number with three significant figures.

2007-05-19 07:58:58 · 1 answers · asked by Division12 2

2007-05-19 07:08:59 · 9 answers · asked by Vanna 1

And how stable is it when you make it before it turns to sulfate?

2007-05-19 07:08:01 · 2 answers · asked by Joseph Z 1

You have a 200.0 mL graduated cylinder containing 51.7 mL of water. A piece of metal with a density of 8.55 g/cm3 weighing 52.50 g is placed in the cylinder. What is the reading on the cylinder after the metal has been added? Enter your answer with the correct number of significant figures.

2007-05-19 06:56:46 · 4 answers · asked by Division12 2

10 grams of Helium
2 moles of Helium
1.8 x 10 to the 24th power atoms of Helium

2007-05-19 06:54:45 · 4 answers · asked by chemistry bum 1

I know the first electron is always 2

2007-05-19 06:45:54 · 1 answers · asked by Anonymous

I need this information for a project I'm doing on Zinc. Any information on Zinc is much appreciated!!! Also does anyone know any experiments I can do with Zinc, that will only a matter of seconds? Thanks, everyone.

2007-05-19 06:44:15 · 3 answers · asked by Ray C 2

The heat lost by the metal block (originally at 100 degrees C) equals the heat gained by the cold water. If the mass of the metal block is 8.10 grams, the temperature of the cold water extrapolated forward to the time of mixing is 16.3 degrees C, and the temperature of the metal block and water mixture extrapolated back to the time of mixing is 37.0 degrees C, what is the specific heat of the metal? Enter your answer with three significant figures in units of J/K.g.

2007-05-19 06:43:32 · 1 answers · asked by Division12 2

2007-05-19 06:40:38 · 2 answers · asked by chemistry bum 1

xplain practical problems..

2007-05-19 06:39:23 · 5 answers · asked by dineshbabu 2