Chemistry - April 2007

why a saturated solution in contact with some undissolved solid is considered to be an equilibrium situation?

2007-04-02 07:23:32 · 6 answers · asked by reem h 2

what`s hotter when water melts or when water freezes

2007-04-02 07:13:17 · 17 answers · asked by Anonymous

2007-04-02 07:11:21 · 2 answers · asked by kelly w 1

Explain why the synthesis proposed would have a low yield and suggest how the synthesis should be SLIGHTLY altered to increase the yield.

2007-04-02 07:07:52 · 3 answers · asked by afchica101 1

I'm having trouble with the products and the products' name of these reactions. If anyone can help, your response will greatly be appreciated.

CH3CH=CHCH3 + HOH ---->

A Hexagon (6 sides) with one double bond + HOH ---->

2007-04-02 06:59:53 · 2 answers · asked by maya 1

2007-04-02 06:57:45 · 1 answers · asked by nrtaopib 1

A certain weak acid,HA , with a Ka of 5.61 *10^-6 ,is titrated with NaOH . A solution is made by mixing 7.00 millimoles of HA and 1.00 millimoles of base and the resulting pH is 4.47. More strong base is added until the equivalence point is reached. What is the pH of this solution at the equivalence point if the total volume is 80.0 mL ?

Please try and show all steps bc i have a test tom. Thanks in advance!!!!!

2007-04-02 06:32:14 · 1 answers · asked by Anonymous

Consider the reaction shown below.
4 PH3(g) ==> P4(g) + 6 H2(g)

If, in a certain experiment, over a specific time period, 0.0035 mol PH3 is consumed in a 1.5 L container each second of reaction, what are the rates of production of P4 and H2 in this experiment?

P4 = ??? mol/Ls

H2 = ??? mol/Ls

2007-04-02 06:05:23 · 3 answers · asked by Anonymous

Hi,

I'm having trouble with my AP Chemistry Homework. The problem I'm stuck on is this:

Consider a solution that is made by dissolving 5.2 g of hydrogen iodide (HI) in 2.0 L of pure water at 25oC.
What is the hydronium ion concentration of this solution?

I've figured out the number of moles of HI, .0407, and its initial concentration is .0203 M. Then I constructed an equilibrium table and got the equation Ka = (x^2) / (.0203 - x). From here, though, I don't know how to proceed, as all of the example problems and other problems on the worksheet give the Ka or Kb for the reactant. Can anyone help explain how to solve this problem? Thanks.

2007-04-02 06:02:19 · 1 answers · asked by eyanyo13 3

2007-04-02 05:58:59 · 2 answers · asked by shortydidi03 2

Help!

1. Water is decomposed into Hydrogen (H2) gas and oxygen (O2) gases according to the following balanecd chemical equation. Answer the questions below regarding what would be produced if 0.50 moles of h20 undergoes decomposition:

2 H^2O(l) ---> 2 H^2(g) + O2(g)
(A) how many moles of 02 are produced when 0.50 moles of water are decomposed
(B) how many grams of H2 are produced when 0.50 moles of water are decomposed?

2007-04-02 05:38:24 · 3 answers · asked by num1grl 2

Or does it have 0?

2007-04-02 04:59:45 · 7 answers · asked by Anonymous

2007-04-02 03:42:36 · 4 answers · asked by greeny36uk 1

we know the mass of carbon is 12g/mol
and avagadros number is 6/02x10^23 molecules/mol

2007-04-02 03:14:04 · 3 answers · asked by Anonymous

any other homesteading info is also useful

2007-04-02 03:10:29 · 2 answers · asked by dragonx_chaosbringer 2

which one is the correct ?

A main group element
B halogen
C transition metal
D alkali metal
E alkaline earth metal

THANKS!

2007-04-02 02:44:36 · 1 answers · asked by Anonymous

2007-04-02 02:01:21 · 7 answers · asked by red devil 4

Explain the purpose of adding sodium hydroxide and copper sulfate In Biuret test.

NaOH:_____________________________
CuSo4:___________________________

2007-04-02 01:55:11 · 6 answers · asked by Unknown 1

2007-04-02 01:12:11 · 1 answers · asked by Anonymous

why is the atomic radius of a halide ion larger than teh radius of its atom?? urgent!!

2007-04-02 01:02:24 · 7 answers · asked by i_luv_leoku_4eva 1

for my calculations i need to know how many ml of water there is in 15ml of Hydrochloric acid (conc. 2M). Please help asap!!

2007-04-02 00:59:25 · 4 answers · asked by Oli 1

Note: Azo compounds refer to chemical compounds bearing the functional group R-N=N-R',

Hoping to learn the physics behind it. :)

2007-04-02 00:26:47 · 1 answers · asked by Anonymous

do all proteins have their own primary, secondary and tertiary structure?

2007-04-01 23:34:10 · 3 answers · asked by kennie 2

2007-04-01 22:35:06 · 2 answers · asked by Anonymous

any help would be greatly appreciated!!!

2007-04-01 22:00:55 · 3 answers · asked by A Solitary Smile 1

2007-04-01 21:02:56 · 1 answers · asked by GOGA 1

I heard helium can damage your voice box and brain cells? WHAT! lol! is that true???

2007-04-01 20:35:53 · 3 answers · asked by Anonymous

a. Ba(NO3)2, barium nitrate
b. NO3-, nitrate ions
c. Na+, sodium ions
d. NaOH, sodium hydroxide
e. OH-, hydroxide ions
f. Ba+2 , barium ions

2007-04-01 19:29:33 · 1 answers · asked by Anonymous

2007-04-01 17:49:43 · 4 answers · asked by Qian Z 1

2007-04-01 17:48:31 · 3 answers · asked by knswalker 1