Chemistry - April 2007

I made a chemical combustion laser years ago that shot a jet black laser beam from it I cant remember the chemicals. By light spectometry or other science detection what where the two chemicals used to get the black wavelength?

2007-04-02 12:06:53 · 1 answers · asked by Anonymous

CaCO3(s) + 2HCl + 5H2O(l) --------> CaCl2 x 6H2O(s) + CO2(g)

2007-04-02 12:05:29 · 2 answers · asked by jagbusiness 1

I need help with this! It's one of my Chemistry questions and any answers I find make no sense to me...Help!

2007-04-02 11:56:10 · 3 answers · asked by Kay 1

Explain why glass, which is made mainly of SiO2(subscript), is often used to make cookware. (Hint: what properties does SiO2 have because of its structure?)

2007-04-02 11:37:48 · 3 answers · asked by TheGreatest 3

Predict which molecules have a greater atteaction for each other, C3H8O(subscripts) molecules in liquid rubbing alchohol or CH4 molecules in methane gas.

2007-04-02 11:35:47 · 3 answers · asked by TheGreatest 3

If anyone could help me figure these out I would greatly appreciate it. I have a test tomorrow and these are the only 2 I can't figure out from my review sheet.

An unknown gas occupies a volume of 1.250 L at 26oC and 705 torr. If the sample has a mass of 2.37 g, what is the molar mass of the gas?
(R = 0.0821 L.atm/mol.K)

AND

How many moles of helium gas occupy a volume of 58.7 L at -13.0oC and 1.17 atmospheres of pressure?


BEST ANSWER TO FIRST CORRECT!!!

2007-04-02 11:08:38 · 2 answers · asked by Anonymous

Is it because they are salts?

2007-04-02 11:04:35 · 2 answers · asked by Anonymous

2007-04-02 09:59:32 · 5 answers · asked by Sandra Dee 1

Relate the order of activities of the halgens to their position on the Periodic Table, and if there a similar trend presents itself with teh metals in the activity chart.

2007-04-02 09:47:05 · 3 answers · asked by Samantha S 1

2007-04-02 09:41:16 · 6 answers · asked by boyzmadison 3

Which is the limiting reagent?
2.000g C7H6O3(salicylic acid) + 5.00mL C4H6O3(acetic anhydride) -->C9H8O4(asprin) + HC2H3O2(acetic acid)

D=1.08g/mL

How many grams of Asprin should be produced from the reaction mixture?

2007-04-02 09:33:43 · 2 answers · asked by bigtex24769 1

I need both the complete chemical equation and the net ionic equation and i can't find either anywhere! Thanks!
K2S2O8 + KI.....???

2007-04-02 09:33:42 · 2 answers · asked by lila 1

i cant figure out how to solve this problem

Hydrochloric acid is usually purchased in concentrated form with a 37.0% HCl concentration by mass and a density of 1.20 g/mL. How much of the concentrated solution in milliliters should you use to make 1.5 L of 0.535 M HCl?
_______ mL

2007-04-02 09:31:07 · 2 answers · asked by Krazyk78 1

Here it is:
Express the rate of reaction in terms of the change in concentration of each of the reactants and products:

A(g) + 2B(g) -> C(g)

When [B] is decreasing at 0.331 mol/(L s), how fast is [A] decreasing?

2007-04-02 09:28:00 · 2 answers · asked by Natalia 3

2007-04-02 09:20:41 · 3 answers · asked by miranda h 1

2007-04-02 09:18:02 · 2 answers · asked by McMaster 2

A certain compound was found to have a molar mass of 72.106 g. A 1.825 g sample of this compound was burned in pure oxygen gas. The measured amount of CO2 produced was 4.455 g, while that of H2O was 1.824 g. No other products were produced in the reaction.

How many moles of hydrogen were in the original sample that underwent combustion ?

2007-04-02 09:11:16 · 2 answers · asked by ashleyjohn18 1

2.000g C7H6O3(salicylic acid) + 5.00mL C4H6O3(acetic anhydride) -->C9H8O4(asprin) + HC2H3O2(acetic acid)
\
Which is the limiting reagent?

How many grams of Asprin should be produced from the reaction mixture?

2007-04-02 09:09:45 · 1 answers · asked by bigtex24769 1

2007-04-02 08:59:47 · 6 answers · asked by McMaster 2

acid.

2007-04-02 08:59:23 · 2 answers · asked by shortydidi03 2

2007-04-02 08:30:18 · 8 answers · asked by Anonymous

I have done a redox titration with sodium thiosulphate and copper sulphate to find the concentration of copper ions. I used potassium iodide. I know the reactions that happen, but I can't figure out how to use the info that I have (average titre, conc., no. of moles, etc) to work out what the concentration of copper ions is.

2007-04-02 08:17:50 · 2 answers · asked by Low profile 3

3-methyl-2pentanol.

2007-04-02 08:05:10 · 3 answers · asked by shortydidi03 2

2007-04-02 07:59:49 · 1 answers · asked by nrtaopib 1

2007-04-02 07:50:28 · 1 answers · asked by the white cloud 1

Which molecule from this list should have the largest partial positive and negative charges: NO, CO2, O2, CH4, NH3. Why?

2007-04-02 07:41:10 · 3 answers · asked by Anonymous

Calculate the lattice energy for LiF(s) given the following:

sublimation energy for Li(s) +161 kJ/mol
DHf for F(g) +77 kJ/mol
first ionization energy of Li(g) +520. kJ/mol
electron affinity of F(g) -328 kJ/mol
enthalpy of formation of LiF(s) -617 kJ/mol


A. 285 kJ/mol
B. -650. kJ/mol
C. 800. kJ/mol
D. -1047 kJ/mol
E. None of these

2007-04-02 07:37:58 · 2 answers · asked by Anonymous

Which of the following ionic compounds has the largest lattice energy, i.e., the lattice energy most favorable to a stable lattice?


A. CsI
B. LiI
C. LiF
D. CsF
E. MgO

2007-04-02 07:36:38 · 1 answers · asked by Anonymous

Which of the following ionic compounds has the least favorable lattice energy?


A. NaCl
B. BaO
C. MgO
D. MgS
E. BaS

2007-04-02 07:36:06 · 1 answers · asked by Anonymous

2007-04-02 07:26:44 · 8 answers · asked by kelly w 1