Chemistry - April 2007

what happens when you precipitate ZnS without a complete seperation of Fe^3+^ beforehand?

2007-04-24 15:47:57 · 1 answers · asked by BMac 3

1. what is the concentration of a household (NH4OH) cleaning soln in 49.90mL of .590M HCl is required to neutalize25.00mL soln?
2. given 238ml of sulfuric acid, find moarity when 34.2mL of lithium hydroxide is used to titrate 15.0mL of the acid?

2007-04-24 15:38:45 · 1 answers · asked by a.h. 2

2007-04-24 15:28:38 · 13 answers · asked by xinnybuxlrie 5

2007-04-24 15:20:33 · 3 answers · asked by witchydee 1

2007-04-24 15:16:35 · 5 answers · asked by Sakura_ssj 2

2007-04-24 15:10:32 · 4 answers · asked by huh 1

When it comes to lewis dot structures, what are the differences between orbital geometry and molecular geometry?

2007-04-24 15:07:25 · 1 answers · asked by bubble 3

When balancing equations, it is important to change only the subscripts and not the coefficients.


A. true B. false

2007-04-24 15:03:50 · 6 answers · asked by Anonymous

2007-04-24 14:56:12 · 1 answers · asked by Celia 4

1. Tungsten (W) can be produced from its oxide by reacting the oxide with hydrogen at high temperatures, according to the following reaction:
WO3 + 3H2 → W + 3H2O

a) What is the percent yield if 56.9 g of WO3 yields 41.4 g of tungsten?

b) How many moles of tungsten will be produced from 3.72 g of WO3 if the yield is 92.0%?

c) This reaction is carried out in the lab, and 11.4 g of tungsten are obtained. If the percent yield is 89.4%, what mass of WO3 was used?

2007-04-24 14:53:56 · 3 answers · asked by sukeschool 1

1. The element arsenic can be commercially produced when arsenic (III) oxide is heated with carbon in this reaction:
2As2O3 + 3C → 3CO2 + 4As

a) If 8.87 g of As2O3 is used in the reaction and 5.33 g of As is produced, what is the percent yield?

b) In a separate reaction, if 67 g of carbon is used up and 425 g of As is produced, calculate the percent yield of this reaction.

2. Nitrogen dioxide, NO2, can react to form dinitrogen pentoxide, N2O5, by reacting with ozone, O3. The reaction occurs according to this equation:
2NO2 (g) + O3 (g) → N2O5 (s) + O2 (g)

a) Calculate the percent yield for a reaction where 0.38 g of NO2 reacts and 0.36 g N2O5 is produced.

b) What mass of N2O5 will result from the reaction of 6.0 mol of NO2 if there is a 61.1% yield in the reaction?

2007-04-24 14:52:12 · 2 answers · asked by sukeschool 1

2007-04-24 14:48:53 · 1 answers · asked by Richi C 1

what would happen to our boddies?

2007-04-24 14:46:20 · 2 answers · asked by Alexis R 1

Lab expierment when we put AlkaSeltzer in a balloon and 5ml of water. Then we tied it up quickly. What is the chemical equation?? PLEASE HELP

2007-04-24 14:36:12 · 2 answers · asked by Anonymous

what is it?
what kind of reactions does it undergo?

how would it react with an amide (+heat)?
i care more about the mechanism than the product.
i just want to understand.

2007-04-24 14:36:11 · 2 answers · asked by Anonymous

please explain:
1. what is the concentration of a household (NH4OH) cleaning soln in 49.90mL of .590M HCl is required to neutalize25.00mL soln?
2. given 238ml of sulfuric acid, find moarity when 34.2mL of lithium hydroxide is used to titrate 15.0mL of the acid?

2007-04-24 14:34:23 · 1 answers · asked by a.h. 2

2007-04-24 14:33:41 · 1 answers · asked by bucknut58d 2

0.1 M KI, 0.1 M KBr, CCl4, NaOCl, and 3M H2SO4. Those are all the solutions I need and I need to make them from scratch. I need a reliable website that could be sited so none of that ".com" crap. It needs to be under ".org" and ".gov". Please help.

2007-04-24 14:29:25 · 1 answers · asked by nc123135 1

1. H2 + O2 -> H20
2. S8 + O2 -> SO3
3. HgO-> Hg +O2
4. Zn +HCl -> ZnCL2 + H2
5. Na + H2O -> NaOH + H2

2007-04-24 14:29:09 · 5 answers · asked by Anonymous

what natural compounds contain chlorine?

2007-04-24 14:26:16 · 17 answers · asked by Alexis R 1

2007-04-24 14:22:57 · 1 answers · asked by JOE Z 1

Currently using simethicone to reduce foaming in E. coli production. Recently we have not been able to control the foaming with simethicone, but have made no known changes to the process. Thinking a possible chemical contaminant effecting simethicone antifoam ability?

2007-04-24 14:16:43 · 2 answers · asked by Crissy_Jo 2

I need to know why or why not preferably in detail because I am writing a lab report. Also if anyone could tell me of copper nitrate, lithium nitrate, calcium nitrate, potassium nitrate barium nitrate and sodium nitrate are metal ions
Please Please Please help thanks

2007-04-24 14:09:26 · 3 answers · asked by Anonymous

2007-04-24 13:50:24 · 4 answers · asked by Anonymous

I have 5 grams of CU and 25 Degrees Celsius right now... after injecting 5,000,000 KJ of heat energy what is the final temperature?

here is the information about CU required to solve it..
ΔH (Fussion) - 1326 KJ/Mole
Melting Point - 1085 Degrees Celsius
Specific Heat Capacity - 24.4 J/Mole degree C
ΔH (Vap) - 300.4 KJ/Mole
Boiling Point - 2562 degrees celsuius

2007-04-24 13:29:44 · 1 answers · asked by Abdul S 3

can you die from eating too much gold? and if you can, how much gold would it take?

2007-04-24 13:29:18 · 2 answers · asked by john opt 1

I had to make a box that was 22,400 cubic centimeters and now I have to calculate the mass and volume of Helium that would fill that box. How do u do it?

2007-04-24 13:16:15 · 3 answers · asked by Anonymous

A solution of strontium hydroxide with a pH of 11.4 is to be prepared. What mass of Sr(OH)2 would be required to make 1.00 L of this solution?

Please show all your work. Thanks

2007-04-24 12:53:25 · 1 answers · asked by Bunny Slippers 1

A buffered solution is made by adding 50.0g NH4Cl to 1.00L of a 0.75M solution of NH3. Calculate the pH of the final solution (assume no volume change)

what do i do?!?!
thanks!

2007-04-24 12:44:48 · 2 answers · asked by sandcastlesinair 1

I already tried but I think I'm doing these wrong. I am not sure how to write the moles with M as the unit...and reactions with acids and bases in general.

Given : Zn, Mg, Fe, Cu

Write balanced molecular equations for the reaction of:
1. each metal with 6M HCl


2. each metal with 6M HC2H3O2

3. CaCO3 with HCl

4. HCl with NaOH

Thanks for any help.

2007-04-24 12:35:46 · 1 answers · asked by ♥♥♥♥♥ 5