Chemistry - November 2006

I need help setting up this word problem:

How many calories of heat are needed to change 35.0 grams of water at 100 degrees Celsieus to water vapor at 100 degrees Celsieus?

2006-11-02 11:36:29 · 1 answers · asked by Mia16 3

what is the difference?

2006-11-02 11:35:42 · 1 answers · asked by kyle k 1

A pharmacist wishes to make 1.8 L of a 10% solution of boric acid by mixing 7.5% and 12% solutions. How much of each type of solution should be used?

2006-11-02 11:34:03 · 3 answers · asked by Amanda 4

2006-11-02 11:33:47 · 6 answers · asked by Joey G 2

i'm doing an assignment about alloy...besides wikipedia,where can i find more about alloy?? i need :-

1.purpose of making alloy
2.examples of alloys,their composition, and properties.
3.difference in properties of metal and its alloy due to difference in arrangement of atoms.

instead of giving me "use yahoo or google sites",its better than you give me the website..Thank you for your help.

2006-11-02 11:17:03 · 1 answers · asked by woolala 2

Ok, so I know atoms are composed of Neutrons and Protons with electrons floating around them. But what makes up the protons and neutrons? Charges? And if so, what makes up those charges?

Theoretically, does it just keep going down smaller smaller? IS there anything that isnt made up of something?

2006-11-02 11:01:23 · 4 answers · asked by Anonymous

Exactly 1/16 of a given amount of protactinium-234 remains after 26.76 hours. what is the half-life of protactinium-234?

How do i carry out this problem? [details please]

*PLEASE HELP*

2006-11-02 10:33:58 · 3 answers · asked by Anonymous

2006-11-02 10:31:35 · 1 answers · asked by Anonymous

"The atomic mass of copper is 63.540 amu. There are two isotopes, Cu-63 and Cu-65 having atomic masses of 62.930 amu and 64.928 amu respectivlery. What is the relative abudance of these isotopes in naturallal occuring samples of copper?"

Normally I would multiply 63 and 65 (the atomic masses) by a percentage but there is not percentage given. How do I solve this equation?

2006-11-02 10:16:57 · 3 answers · asked by mbtafan 3

2006-11-02 10:04:44 · 4 answers · asked by ringo 1

i went to two diff sites and theyr telling me something that it in both sections its so stupid. i know i may be looking at the wrong sites but none of the sites blandly explain each.................please if you can provide something.....do it without stupid remarks........thnx :)

2006-11-02 10:04:15 · 6 answers · asked by chris ;) 1

2 AGNO (aq) + NA S(aq) ---> Ag S(s) +2NaNO
............3 .............2 ................2 ................3

2006-11-02 10:01:02 · 2 answers · asked by ShanAnn B 1

2006-11-02 09:44:38 · 4 answers · asked by manda show 1

2006-11-02 09:42:07 · 1 answers · asked by dramaqueen9261 1

When making a batch of the mertial, you must add the proper amount of a .36 M sodium sulfate solution to precipitate all the barium in 5.00 L of a 0.15 M barium nitrate solution. Teh reaction occurs as follows:
Na SO (aq) + Ba(NO ) (aq)----> 2 NANO (aq) +
2 4 3 2 3
BaSO (s)
4
The lower numbers go halfway between the letters.

2006-11-02 09:40:12 · 2 answers · asked by ShanAnn B 1

and can i also have the word equation for it too.

Iron (III) oxide is a rust in an oxide

2006-11-02 09:35:37 · 6 answers · asked by jenny. 2

2006-11-02 09:24:40 · 1 answers · asked by Sarah 1

after 4 minutes.
Relative atomic mass H=1,0=16.

2]Using 0.3 mol dm hydrogen peroxide.Give one reason for the answer if it were to be carried out as a experiment.Please show working cause i don't really understand it.

2006-11-02 09:17:22 · 2 answers · asked by Anonymous

for example i need to know the hazards of sodium phenoxide and many others.

2006-11-02 09:15:52 · 2 answers · asked by Anonymous

I was just wondering if the sp3, sp2, sp hybrid orbitals always form sigma bonds? what about the p orbitals..do they always form pi bonds?

2006-11-02 09:08:14 · 3 answers · asked by geeky girl 1

The equilibrium constant for the reaction below is Kc = 9.1 10-6 at 298 K.

2 Fe3+(aq) + Hg22+(aq) <--> 2 Fe2+(aq) + 2 Hg2+(aq)

Calculate the change in G when [Fe3+] = 0.29 M, [(Hg2)2+]= 0.029 M, [Fe2+] = 0.028 M, and [Hg2+] = 0.040 M.

In which direction will the reaction proceed to achieve equilibrium? (right or left?)

2006-11-02 09:00:54 · 1 answers · asked by tigergurrl34 1

a.) it decreases
b.) it stays constant
c.) it increases
d.) it varies, depending of the identitiy of the liquid

2006-11-02 08:58:39 · 5 answers · asked by Anonymous

2006-11-02 08:53:31 · 6 answers · asked by DONNA M 1

In (MoO )
2 4 3
The numbers are spaced half way below each element. I just can't make the computer do that with this set-up

2006-11-02 08:50:08 · 1 answers · asked by ShanAnn B 1

I came up with 2NI3 ---> N2 + 3I2, double replacement and Al2(SO4)3 + 6NaOH ---> 2Al (OH)3 + 3Na2SO4 double replacement am I on the right track

2006-11-02 08:35:05 · 2 answers · asked by Anonymous

1.A photon of visible light has sufficient energy to excite the electron from the n=2 to the n=6 energy state.

2.The wavelength of light emitted when the electron returns to the ground state from n=3 will be the same as the wavelength of light absorbed to go from n=1 to n=3.

3.For n=3, the electron is in the first excited state.

4.The frequency of light emitted when the electron drops from n=5 to n=2 is less than the frequency of light emitted when the electron drops from n=4 to n=1

2006-11-02 08:31:20 · 4 answers · asked by Juan V 1

A) Ca(s) Ca2+(aq)
B) Hg(I) Hg2+(aq)
C) Fe+2(aq) Fe3+(aq
D) NO3- (aq) NO(g)
E) SO3 2-(aq) SO4 2-(aq)

2006-11-02 08:07:28 · 2 answers · asked by help_w_homeowrk 1

2006-11-02 08:06:44 · 5 answers · asked by samii 2

2006-11-02 07:46:01 · 5 answers · asked by Anonymous

is copper a metal or nonmetal?

2006-11-02 07:22:58 · 10 answers · asked by Anonymous