Chemistry - April 2007

What is the solubility of CuCl when it is in a solution of 0.35 M NaCl? Oh, and, by the way, CuCl has Ksp = 1.9 x 10^-7.

2007-04-14 10:20:54 · 1 answers · asked by theweirdguy1 2

2007-04-14 10:19:56 · 2 answers · asked by Anonymous

2007-04-14 10:18:34 · 1 answers · asked by theweirdguy1 2

O2
CO32-
PH3
N2H4
CH4
CCl4
OH1-

2007-04-14 10:09:23 · 2 answers · asked by l_walker2005 1

hi guys...well my dilemma is that i NEED TO WORK OUT THE PERCENTAGE ERRORS.....well , firstly the minimum error for a burette is 0.05 so, eg. (0.05/50mL x 100 = 0.1)...ok thats the begining...but i have also found somewhere that...

"when you use a burette you take a reading at the start and the end , so you have two errors of 0.05 cm3 i.e. total error = 0.10 cm3. If you are using your burette to do a titration there may be another error of one or two drops which is due to your judgement of when the indicator changes colour. This means that in a titration (as opposed to just using a burette to measure a volume) you may have an error of 0.2 cm3."

so...(0.2/watever measurement x100)...BUT..in my past courseworks..i divided (0.05/ measurement x 100)..and i REALLY DO NOT KNOW WHICH ONE IS RIGHT???

i dont know whether i shud do % errors for every repeated experiment i have dne for that 1 test??or just for one...i just dont know which error to USE 0.05 or 0.2 AARGH!!! PLZ HELP ME !!?

2007-04-14 09:52:31 · 4 answers · asked by ang3lbluff 1

If a solution of CaF2 has [Ca++] = 3.1 x 10^-4 and [F-] = 1.5 x 10^-3, and if PbI2 has Ksp = 3.9 x 10^-11, will a precipitate form in the solution?

2007-04-14 09:49:26 · 2 answers · asked by Random G 3

A buffer solution is prepared by mixing 600.0 ml of 0.600 M HClO and 400.0 ml of 1.00 M NaClO. Calculate the pH of the solution after 40.0 ml of 3.00 M HCl is added to the buffer. For HClO, Ka = 3.0X 10^-8.

To do this I determined the concentration of H+ before the HCl was added and assumed that the H+ of HCl would join the excess ClO in the solution, thus making a negligible effect on the pH (the excess H+ of the HCl would be used up). My final answer was pH = 4.936

2007-04-14 09:46:31 · 1 answers · asked by elizabeth_is_a_fiesty_gal 2

because i want "koh" tattooed and i cant seem to find any picture of the structure. either lewis or the hexagonal thing.
or whatever

2007-04-14 08:52:37 · 1 answers · asked by Steve K 1

Nitric oxide, NO, reacts instantly with oxygen gas to give nitrogen dioxide, NO2, a dark brown gas.
In one experiment 16.81 g of NO is mixed with 10.55 g of O2.


What is the theoretical yield of NO2 ? I.E., how many grams of NO2 should be formed?

2007-04-14 08:33:54 · 1 answers · asked by nicole 1

Nitric oxide, NO, reacts instantly with oxygen gas to give nitrogen dioxide, NO2, a dark brown gas.
In one experiment 16.81 g of NO is mixed with 10.55 g of O2.


What is the theoretical yield of NO2 ? I.E., how many grams of NO2 should be formed?

2007-04-14 08:33:39 · 2 answers · asked by nicole 1

NH3 (aq) + Ni(NO3)2 (aq) ---> ?

2007-04-14 07:52:53 · 1 answers · asked by Christina 2

Your body needs to heat the cold water that you drink to
37.0°C. A slice of cake gives about 1000 kJ of heat when metabolized by your body. How much cold water, at 2.0°C, do you need to drink to make up for (that is, use up the kilojoules gained by) eating a slice of cake?
how would I go about and doing this question? thanks in advance!

2007-04-14 07:48:32 · 1 answers · asked by Anonymous

What is the nuclear equation to represent:

Pu-239 is hit with a neutron to form Ce-146, another nucleus and three neutrons.

2007-04-14 06:28:13 · 3 answers · asked by Anonymous

2007-04-14 06:27:14 · 4 answers · asked by W 1

2007-04-14 06:21:19 · 1 answers · asked by besho 1

2007-04-14 06:03:27 · 3 answers · asked by woojin k 1

2007-04-14 05:57:04 · 2 answers · asked by dancesintherain45 2

A voltaic cell consists of a Ag/Ag+ electrode (E° = 0.80 V) and a Fe2+/Fe3+ electrode (E° = 0.77 V) with the following initial molar concentrations: [Fe2+] = 0.30 M; [Fe3+] = 0.10 M; [Ag+] = 0.30 M. What is the equilibrium concentration of Fe3+? (Assume the anode and cathode solutions are of equal volume, and a temperature of 25°C.)
0.030 M
0.043 M
0.085 M
0.11 M
0.17 M

2007-04-14 05:56:25 · 1 answers · asked by phong pham 2

Examine the following half-reactions and select the strongest reducing agent among the species listed.
HgO(s) + H2O(l) + 2e- ↔ Hg(l) + 2OH-(aq) E° = 0.0977 V
Zn(OH)2(s) + 2e- ↔ Zn(s) + 2OH-(aq) E° = -1.25 V
Ag2O(s) + H2O(l) + 2e- ↔ Ag(s) + 2OH-(aq) E° = 0.342 V
B(OH)3(aq) + 7H+(aq) + 8e- ↔ BH4-(aq) + 3H2O(l) E° = -0.481 V
Hg(l)
Zn(s)
Ag(s)
BH4-(aq)
Zn(OH)2(s)




Examine the following half-reactions and select the strongest oxidizing agent among the species listed.
Cr2+(aq) + 2e- ↔ Cr(s) E° = -0.913 V
Fe2+(aq) + 2e- ↔ Fe(s) E° = -0.447 V
Sr2+(aq) + 2e- ↔ Sr(s) E° = -2.89 V
Co2+(aq) + 2e- ↔ Co(s) E° = -0.28 V
Cr2+(aq)
Fe(s)
Fe2+(aq)
Sr2+(aq)
Co2+(aq)

2007-04-14 05:55:09 · 1 answers · asked by jennifer 2

Given that the electronic configuration of silver is: [Kr] 4d10 5s1
Deduce the colour of [AgCl2]-
Explain your answer.

I have absolutely no idea how to attempt to answer this, what are the steps in doing so? Thanks

2007-04-14 05:51:50 · 1 answers · asked by Anonymous

The ionization constant of a certain acid, HA, is 9.0 x 10(to the negative twelth power) If enough HA is added to water to make a 1.0 M solution, what will be the hydrogen ion concentration?




An acetic acid solution contains 3 g of acetic acid, HC2H302, in .50 dm3. If Ka for acetic acid is 1.8x 10 (to the negative 5), what is the hydrogen in concentration




they are both asking the same thing i jus dont get it i know what Ka is but....please help

2007-04-14 05:38:25 · 2 answers · asked by Anonymous

tungsten can be produced from its oxide by reaction the oxide with hydrogen at a high temperature according to the following equation.

WO3 + 3H2 ---> W + 3H2O

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

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

c) a chemist carries out this reaction and obtains 11.4g of tungsten. If the percent yield is 89.4% what mass of WO3 was used?

2007-04-14 05:33:04 · 2 answers · asked by Lore 1

in the commercial production of the element arsenic,
arsenic (III) oxide is heated with carbon, which reduces the oxide to the metal according to the following equation:

2As2O3 + 3C ----> 3CO2 + 4As

a) if 8.87g of As2)3 is used in the reaction and 5.33g of As are produced, what is the percent yield??

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

2007-04-14 05:29:47 · 1 answers · asked by Lore 1

a double replacement reaction occurs between silver nitrate and magnesium bromide.calculate the mass of silver bromide which should be produced from 22.5g of silver nitrate.
When reacted in the lab, 22.0 grams of silver bromide were actually produce. What is the percent yield?

-how do i do this?? and whats the answer? =/ ((i think i did it wrong i got 88%))

2007-04-14 05:26:12 · 3 answers · asked by Lore 1

2007-04-14 05:20:30 · 2 answers · asked by Anonymous

N2 + 3H2------2NH3
If N2 is 2kg and H2 is 1kg how much NH3 will be evolved? The answer is 2.571 kg but can anyone pls. explain how you're getting it.

2007-04-14 05:19:26 · 2 answers · asked by goodguy 1

a particular organic compound?

2007-04-14 04:50:15 · 2 answers · asked by Anonymous

a. a proton
B. an electron
C. a hydroxide ion
D. hydronium ion

In the competition for a proton in an acid-base reaction the winner is always the
A. stronger base
B. stronger acid
C. amphoteric substance
D. amphiprotic substance

2007-04-14 04:47:00 · 3 answers · asked by Anonymous

I have to name the following chemicals for chemistry:
a. Sns
b. SnS2
c. CoCl3
d. CoCl3
e. HgBr2
Hg2Br2
How do you name these chemicals using the -ous or -ic notation

2007-04-14 04:46:29 · 3 answers · asked by Anonymous

A. weaker acid donates a proton to the weaker base
B. weaker acid donates an electron to the stronger base
C. stronger acid donates a proton to the weaker base
D. stronger acid donates a proton to the stronger base


Dilute acids react with chemically active metals to produce?
A. hydrogen
B.oxygen
C. metal hydrides
D. metal hydroxides

2007-04-14 04:41:44 · 2 answers · asked by Anonymous