Chemistry - October 2007

a .500-g mixture of Cu2O and CuO contains .425 g Cu. What is the mass of CuO in the mixture???

2007-10-02 17:28:28 · 2 answers · asked by hockeykev05 1

Write formulas for these compounds
1. silver sulfide
2. stannic chloride
3. sodium nitride
4. strontium iodide

2. Write the formulas for these compounds

1. mercury (ll) bromide
2. ammonium dichromate
3. lithium hydrogen sulfate
4. chromium (lll) nitrite

2007-10-02 16:41:26 · 3 answers · asked by (: Muffin Man :) 2

The reactions that typically occur when a neutron strikes a uranium-238 nucleus and a uranium-235 nucleus are different. Explain how.


___ A. The uranium-235 nucleus absorbs the neutron and is converted to plutonium-238, whereas uranium-238 undergoes nuclear fission.
___ B. The uranium-238 nucleus absorbs the neutron and is converted to uranium-239, whereas uranium-235 undergoes nuclear fission.
___ C. The uranium-238 nucleus absorbs the neutron and is converted to plutonium-239, whereas uranium-235 undergoes nuclear fission.
___ D. The uranium-235 nucleus absorbs the neutron and is converted to uranium-238, whereas uranium-238 undergoes nuclear fission.

2007-10-02 16:18:37 · 1 answers · asked by Anonymous

each other??? i don't understand what the difference is between a mole and molar mass. how do i find how many atoms are in 2.50 moles of Hydrogen? i really appreciate the help!

2007-10-02 16:14:10 · 5 answers · asked by bella_cullen 1

it need to use noble gas. I got [Ar]4s(2)3d(4), but it's wrong!!! what is the right answer? thank you.

2007-10-02 15:57:41 · 1 answers · asked by meilingqian89 1

Write the balanced net ionic equation for each of these acid-base reactions. Enter the formula of the cation (if any) first, then neutral species (if any), followed by the anion (if any) with coefficients (if needed; do not include 1 as a coefficient). Put charges (if any) in parentheses (multiple first, if any, followed by sign) and phase in parentheses, e.g., Al3+(aq) should be entered as Al(3+)(aq). In each case, write the formulas of the spectator ions.

HBr(aq) + NH3(aq) ?
ive got a part of this

____+ NH3(aq) ---> NH4(+)(aq) +______

HClO(aq) (a weak acid) + NaOH(aq) ?
i got part of this too
HClO(aq) + ______---->______ + _______

HClO4(aq) + Ca(OH)2(aq) ?
i got a part of this one too

H3O(+)(aq) + ________ -----> ________

Identify the spectator cation= Ca(2+)(aq)
what is the spectator anion= i have no idea

2007-10-02 15:32:51 · 1 answers · asked by Anonymous

Okay, is the most mass of an atom in the nucleus or outside of it? & explain. I'm stuck! =[

2007-10-02 15:30:13 · 6 answers · asked by Anonymous

Some of the following react when added together, but others do not. For those that do, write a balanced net ionic redox equation. Enter the formula of the cation (if any) first, then neutral species (if any), followed by the anion (if any) with coefficients (if needed; leave 1s off as they are implied). Put charges (if any) in parentheses (multiple first, if any, followed by sign) and phase in parentheses, e.g., Al3+(aq) should be entered as Al(3+)(aq). If there is no reaction, enter none in all the boxes.


HCl(aq) + Al(s) ?

Ive gotten parts of it here is what i have

________+2Al(s) --->_______+ 3H2(g)+______H2O(l)

2007-10-02 15:29:28 · 1 answers · asked by Anonymous

the # of cobalt atoms in .00103 mol of cobalt.


Thanks

2007-10-02 15:04:22 · 1 answers · asked by Angie 2

One of my classmates told me that if at least one of the products of the reaction (if it occurred) is a solid, liquid, or gas, that the reaction will happen, but that if all of the products are aqueous, then it won't occur. However, she also said she wasn't completely sure. Was she right?

2007-10-02 14:04:16 · 2 answers · asked by chucknorris=theman 2

Zinc metal reacts with sulfur to produce a white powder of Zinc sulfide. If 65.4g of zinc reacts with 32.1g of sulfur to form the commpund, calculate how many grams of the compund can be produced from 20.0g of sulfur and enough zinc.

i did 65.4/32.1= 2.037
then 2.037 x20.0g= 40.7
thats as far as i got....

2007-10-02 14:02:56 · 1 answers · asked by Anonymous

I ... kinda solved this problem but I don't think I did it right though.

One chocolate has a mass of 3g. How many chocolates should be in a one-pound bag?

I got 151 and... had to round up for SigFig so I ended up having 200.... and it just doesn't look right...
Can anyone help me? Thank you

2007-10-02 14:00:14 · 1 answers · asked by melong_91 1

How would you calculate the number of H atoms in this sample?

2007-10-02 13:56:07 · 4 answers · asked by Anonymous

The question asks me to draw a Bohr diagram of that atom that shows the number of neutrons, proton, electrons. How many electrons do I draw, and how many protons, and neutrons do I draw.

2007-10-02 13:52:31 · 3 answers · asked by Kenster102.5 6

And why?

2007-10-02 13:49:42 · 3 answers · asked by Anonymous

What makes it possible (structure-wise) to see analgesics under UV light?

2007-10-02 13:48:13 · 1 answers · asked by bdgurl5388 1

2007-10-02 13:46:31 · 3 answers · asked by bwatson200 1

I have a gigantic test tomorrow in chem and I cannot for the life of me figure out how to do these.. if you know how please do them and try to give me some detail as to what you did and possibly why?
Thanks!!

1. Write a net ionic equation for the reaction that occurs when aqueous solutions of hydrocyanic acid and ammonia are combined.

2.Write a net ionic equation for the reaction that occurs when aqueous solutions of acetic acid and ammonia are combined.

2007-10-02 13:44:10 · 2 answers · asked by SweetMandy01234 2

Match each of the following equations with the letter that tells what the pH of the final solutions that form would be.

a. low (about 1-2)
b. moderately low (about 5-6)
c. high (about 13-14
d. moderately high (about 8-9)

1. ___ NaOH + H2O -->

2. ___ NH3 + H2O -->

3. ___ H2O + CO2 -->

4. ___ HCl + H2O -->


1.B 2.D 3.A 4.C?

2007-10-02 13:41:06 · 3 answers · asked by matterized 1

2007-10-02 13:40:01 · 2 answers · asked by Anonymous

its a chemistry question. how many electrons do you think there are in orbit of the elements rb and cs"; 2nd question same but br and i. i told the teacher the amount of electrons in those elements but she said it was wrong. wth?

2007-10-02 13:28:10 · 2 answers · asked by Updated Life th13f 2

When testing vapor pressure with water and t-butyl, n- hexane, cyclohexene, and ethyl ether, what changes would you expect if the water and all of the liquids tested had been heated before the experiment?

2007-10-02 13:24:33 · 1 answers · asked by lovin Chem right now 1

what mass of pheno, C6H5OH, (fw=94.11) must be dissolved in 25 g of naphthalene to produce a solution that is 0.22 m in phenol?

2007-10-02 13:08:07 · 1 answers · asked by Anonymous

Which would have the lowest boiling point?
H2Te
H2O
H2S
H2Se
HI

I'm not sure how you find this so please explain

2007-10-02 13:01:26 · 1 answers · asked by Anonymous

soil
sugar water
alcohol
pure air

2007-10-02 12:53:20 · 4 answers · asked by Anonymous

2007-10-02 12:47:33 · 3 answers · asked by tmmz1107 2

If 70.0 mL of 0.150 M CaCl2 is added to 35.0 mL of 0.100 M AgNO3, what is the mass in grams of AgCl precipitate

2007-10-02 12:42:10 · 1 answers · asked by ws 3

How many centimeters out of the water does a 1.00 cm cube of wood with a density of 0.85g/ml float?

2007-10-02 12:31:28 · 1 answers · asked by Anonymous

2007-10-02 12:21:45 · 4 answers · asked by daryl r 1

A ring wheighing 7.6256g in air weighs 6.9465g when suspended in water at 24 degrees C. If the density of gold is 19.3g/ml, is the ring made of good or some other material?

2007-10-02 12:19:52 · 1 answers · asked by Anonymous