Chemistry - April 2007

What is the value of micron in metres?

2007-04-09 23:52:07 · 2 answers · asked by Kanakathara 1

It's for a 6th grade paper. It's needs to have accurate facts nd im stuck. help please!!!!!!!!!!!!

2007-04-09 23:28:31 · 4 answers · asked by Jordan M 1

I seem to remember us heating wax in summer camp and pouring it into holes in the sand. The sand stuck to the wax. But when I tried heating wax at home as an adult, it turned black and it was also quite a problem to scrape the leftovers out of the pot afterwards. Any advice is welcome.

2007-04-09 22:20:25 · 4 answers · asked by Happy Feet 3

2007-04-09 22:18:39 · 8 answers · asked by hazra b 1

name a gas that is not water soluble,
how do you make that gas, if possible can it be a gas that is produced using an acid.

2007-04-09 22:08:20 · 3 answers · asked by Anonymous

CO2 + H2O
or
SO2 + H2O
out of the two which bonds more readily.

2007-04-09 21:59:19 · 4 answers · asked by Anonymous

2007-04-09 21:56:47 · 6 answers · asked by freean_07 3

2007-04-09 21:15:36 · 2 answers · asked by nomer 1

2007-04-09 21:06:48 · 2 answers · asked by yty . 1

A compound of vanadium has a magnetic moment 1.73BM. Work out the electronic configuration of vanadium ion in this compound.
I got unpaired electron as one and figured out that there should be 21 electrons but the answer says 19 electrons. Could any one explain why?

2007-04-09 21:06:46 · 2 answers · asked by Nikhil 2

a. 5.0g Pyrex® glass (specific heat capacity = 0.20 cal/g•K)

b. 20g platinum (specific heat capacity = 0.032 cal/g•K)

c. 1.0g water (specific heat capacity = 1.00 cal/g•K)

2007-04-09 21:03:07 · 3 answers · asked by bballchic601 1

CAN SOMEONE HELP ME WITH ANSWERS!!!

The pollutant sulphur dioxide can removed from the air by reaction with calcium carbonate in the presence of oxygen. What mass of calcium carbonate is needed to remove 1 tonne of sulphur dioxide?

2 CaCO3 + 2 SO2 + O2  2 CaSO4 + 2 CO2

15) 5.00 g of hydrated sodium sulphate crystals (Na2SO4.nH2O) gave 2.20 g of anhydrous sodium sulphate on heating to constant mass. Work out the relative molecular mass (Mr) of the hydrated sodium sulphate and the value of n.
Na2SO4.nH2O  Na2SO4 + n H2O

16)5.00 g of a mixture of MgSO4.7H2O and CuSO4.5H2O was heated at 120C until a mixture of the anhydrous salts was formed, which weighed 3.00 g. Calculate the percentage by mass of MgSO4.7H2O in the mixture.

2007-04-09 21:02:02 · 2 answers · asked by seksi_mace 1

CAN SOMEONE HELP ME WITH ANSWERS!!!

The pollutant sulphur dioxide can removed from the air by reaction with calcium carbonate in the presence of oxygen. What mass of calcium carbonate is needed to remove 1 tonne of sulphur dioxide?

2 CaCO3 + 2 SO2 + O2  2 CaSO4 + 2 CO2

15) 5.00 g of hydrated sodium sulphate crystals (Na2SO4.nH2O) gave 2.20 g of anhydrous sodium sulphate on heating to constant mass. Work out the relative molecular mass (Mr) of the hydrated sodium sulphate and the value of n.
Na2SO4.nH2O  Na2SO4 + n H2O

16)5.00 g of a mixture of MgSO4.7H2O and CuSO4.5H2O was heated at 120C until a mixture of the anhydrous salts was formed, which weighed 3.00 g. Calculate the percentage by mass of MgSO4.7H2O in the mixture.

2007-04-09 21:01:33 · 2 answers · asked by seksi_mace 1

Calculate the heat necessary to raise the temperature of 40.0g of aluminum from 20.0 degrees C to 32.3 degrees C.

2007-04-09 21:00:26 · 1 answers · asked by bballchic601 1

Please help, answer any of the following questions about these elements, THANK YOU....

Sulfur:
Can it conduct electricity?
Density?
Hardness?
Malleability?
Ductility?
What does it react with?
Any other interesting properties?
Hydrogen:
Can it conduct electricity?
Density?
Hardness?
Malleability?
Ductility?
What does it react with?
Any other interesting properties?
Copper:
Density?
Hardness?
Ductility?
What does it react with?
Any other interesting properties?
Gold:
What does it react with?
Any other interesting properties?

If you answered any of the above questions, thank you sooo much

2007-04-09 20:40:11 · 2 answers · asked by Caity 3

Consider a galvanic cell for the following balanced reaction:
6H+(aq) + 2Al(s) → 2Al+3(aq) + 3H2(g) E°cell = 1.66 V


A. Suppose at 25 degrees Celsius the H (+1) aqueous concentration is 0.1 M, the Al 3+ ion concentration is 1.0 M and the partial pressure of hydrogen gas is 2.0 atm. Calculate the overall emf of this cell.
B. Calculate the change in mass in grams of the aluminum electrode after the cell has supplied a constant current of 10.0 amps for 25.0 minutes..
C. Calculate the free energy change , delta G, for the reaction

2007-04-09 19:57:04 · 1 answers · asked by radmav2001 1

Silver has a face-centered unit cell. The diameter of a silver atom is about 2.90 angstroms. Use this measurement to calculate the density of silver (grams per centimeter cubed)
atomic weight of Silver = 107.87 g/mol

2007-04-09 19:17:39 · 2 answers · asked by evilssjtrunks65 1

If 87g of K2SO4 (molar mass 174g) is dissolved in enough water to make 250 mL of solution, what are the concentrations of the potassium and the sulfate ions?

(A) [K+] = 0.020M [SO4 (-2)] = 0.020 M
(B) [K+] =1.0 M [SO4 (-2)] = 2.0 M
(C) [K+] = 2.0 M [SO4 (-2)] = 1.0 M
(D) [K+] = 2.0 M [SO4 (-2)] = 2.0 M
(E) [K+] = 4.0 M [SO4 (-2)] = 2.0 M

I found the mols of K2SO4 but what do I do after this? Please, can anyone help?? thank you in advance

2007-04-09 19:15:40 · 4 answers · asked by Hola Lola! 2

Another lab question - "Based on your answer to (6) and (8), calculate the volume occupied by 1 mole of H2 gas. Report tihs as the experimental Molar Volume of the gas."

answer to 6 = experimental mole of H2 gas produced = 58.9 mol H2

answer to 8 = volume of H2 gas at STP = 1320 L H2

I'm kind of confused... I'm supposed to use 58.9 mol in solving for the volume, and yet the question also gives a value of 1 mole. Would I use the Ideal Gas equation in this problem? How should the equation be set up like?

Thank you very much, I really appreciate it!

2007-04-09 19:12:05 · 1 answers · asked by fruitxcakee 1

Atoms having greatly differing electronegativities are expected to form:
a. no bonds
b. polar covalent bonds
c. nonpolar covalent bonds
d. ionic bonds
e. covalent bonds

I'm having a hard time between B. and D.
Thanks!

2007-04-09 18:59:52 · 1 answers · asked by sh4olinh 1

A 3.122 g sample of this compound was burned in pure oxygen gas. The measured amount of CO2 produced was 7.415 g, while that of H2O was 3.794 g. No other products were produced in the reaction.

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

2007-04-09 18:35:18 · 1 answers · asked by Anonymous

has an equilibrium constant of .0005 M^-6. solutions were mixed sothat the initial concentration of the Cobaltous ion was 0.100M and the Ammonia was 1.00M. what are the equilibrium concentrations of all 3 species in the reaction?

2007-04-09 18:31:53 · 2 answers · asked by Anonymous

the Ksp=5.6x10 ^ -12 . what is the pH of the saturated soltion of Mg(OH)2?

2007-04-09 18:11:50 · 1 answers · asked by Hello 1

(a) A piston at 8.3 atm contains a gas that occupies a volume of 3.5 L. What pressure would have to be placed on the piston to force the volume to adjust to 1.52 L?
_____ atm

(b) A piston at -34.0°C contains a gas that occupies a volume of 2.5 L. To what temperature would the gas have to be heated to increase the volume to 6.2 L at constant pressure?
____°C

(c) A piston at 6995 torr contains a gas that occupies a volume of 4.7 L. What pressure would have to be placed on the piston to force the volume to adjust to 0.56 L?
_____ atm

2007-04-09 17:43:10 · 3 answers · asked by lola_boo 1

I like to start one unit of manufacturing the material which has high scope in my country.

2007-04-09 16:58:41 · 1 answers · asked by kunhimohamedk 1

Which of the following are true statements about CO2 ?



a) The melting point of CO2 increases as pressure increases


b) The critical point of CO2 occurs at −57oC and 5 atm


c) At 20oC and 3 atm CO2 is in the gas state


d) At 20oC and 1 atm, solid CO2 will sublime


e) Above 31oC and 31 atm CO2 can not be compressed to the liquid state
under any amount of pressure

2007-04-09 16:56:26 · 1 answers · asked by matthew204342000 1

1. Benzoic acid, C6H5COOH, dissociates in water. C6H5COOH (s) ---> C6H5COO-(aq) + H+(aq) ka= 6.46x10^-5. A 25.0ml sample of an aqueous soln of pure benz. acid it titrated usin standardized 0.150M NaOH
a.) after addition of 15.0ml of the 0.150M NaOH, the pH of the soln= 4.37 calculate the following:
* [H+] in soln
* [OH-] in soln
* the # of moles of NaOH added
* The # of moles of C6H5COO- (aq) in soln.
* The # of moles of C6H5COOH in soln.
b.) State whether the soln at the equivalence point of the titration is acidic, basic, or neutral. Explain your reasoning

In a different titration, 0.7529g sample of a mixture of solid C6H5COOH and solid NaCl is dissolved in water and titrated with 0.150M NaOH. The equivalence point is reached at 24.78mL of the base soln is added
c.) calculate each of the following:
* The mass, in grams of benzoic acid in the solid sample.
* The mass percentage of benzoic acid in the solid sample.

2007-04-09 16:43:46 · 2 answers · asked by nickesha t 2

Which of the following are true statements about CO2 ?
a) The melting point of CO2 increases as pressure decreases
b) The critical point of CO2 occurs at 31oC and 73 atm
c) At −20oC and 12 atm CO2 is in the liquid state
d) At 20oC and 1 atm, solid CO2 will melt to liquid state
e) Above 31oC a pressure greater than 73 atm would condense CO2 to the liquid state

2007-04-09 16:38:05 · 1 answers · asked by Anonymous

http://capa.chem.sunysb.edu/nan/unitcell.GIF
The unit cell of the mineral perscovite is shown above. What is the chemical formula of perscovite in the form CaxTiyOz ?

Enter an answer in the form, for example, CaTi2O4 for CaTi2O4

2007-04-09 16:35:31 · 1 answers · asked by Anonymous

The below reaction results in two moles of a single ionic compound as a product.

4V + O2 -->

What is the name of the compound ?

An example of the correct answer format would be lead(II) nitrate note the space

2007-04-09 16:26:47 · 2 answers · asked by Anonymous