Chemistry - February 2007

Please list the sources you used for finding the answer. Thank you!

2007-02-06 16:14:34 · 7 answers · asked by kmann882002 2

2007-02-06 15:59:26 · 12 answers · asked by awantwin2004 2

Heres the question. plz explain how to do it also

Ideal gas law: PV=nRT
(*=degrees)
A mass of 5g of solid(specific heat 2.08 J/g.K) initially at 100*C is droppe into a beaker containing 100g of water (specific heat 4.18 J/g.k) initially at 25*C. Assuming that the heat lost by the solid is gained by the water body, find the final temperature of the system (water + solid).

a)26.8*C
b)30.2*C
c)36.8*C
d)50.0*C

2007-02-06 15:57:34 · 3 answers · asked by aznfobboytly 3

a typical car gets 30 mpg of gas & drives 12000 mi per yr. assuming that octane (C8H18 density 0.07025) is a principal component of gasoline;
a. how much oxygen is required for a car to run for 1 yr?
b. how many grams of CO2 is produced by a car in 1yr?

the chemical formula for gasoline is :
2 C8H18 + 25 O2 -> 18 H2O + 16 CO2

2007-02-06 15:51:02 · 2 answers · asked by switchfootgrl810 1

If a certain source emits radiation of wavelength 360. nm what is the energy, in kJ, of one mole of photons of this radiation?

2007-02-06 15:12:28 · 2 answers · asked by Anonymous

1 Given the following thermochemical equation:
2Fe2O3+3C=>4Fe+3CO2 q= -2310KJ
If a reaction has a heat change of -328KJ, what quantity of Fe2O3 in moles reacted?

2 Given the following thermochemical equation:
FeS+2HCl=>FeCl2+H2S q= -1230KJ
What is the heat change in KJ accompanying the production of 1.43moles of H2S?

3Given the following thermochemical equation:
4C2H3O2Br+3O2=>8CO+6H2O+2Br2 q= 2910KJ
What is the heat change in KJ accompanying the production of 13.8grams of H2O?

2007-02-06 15:10:27 · 1 answers · asked by Ellie 1

2007-02-06 14:51:22 · 4 answers · asked by Anonymous

do anybod know what is the ionic equation???
thanks!! :)

2007-02-06 14:42:03 · 1 answers · asked by GinBerry 1

can you please explain it to me, or tell me about a good site i could visit, that would explain it for me.

2007-02-06 14:31:19 · 2 answers · asked by masry 2

2007-02-06 14:29:05 · 4 answers · asked by Anonymous

the symbol is Ni

2007-02-06 14:28:09 · 4 answers · asked by Anonymous

2007-02-06 14:26:55 · 3 answers · asked by kmann882002 2

With respect to N2 O3
It asks what the mass of 1 mol, 5 mol, and 0.5 mol is.
How would you find the mass though...I don't get it

Also, it asks to calculate the % composition of nitrogen in the compound...I'm not sure of how to find that either

Any sort of help would be great. Thanks =)

2007-02-06 14:26:00 · 1 answers · asked by A 2

f(x)={-1/2x if x< 3
{2-8x if x is greater or equal to

2007-02-06 14:16:02 · 2 answers · asked by whitmo2004 1

A 50.0 g piece of matal at 60.0 degree C contained in a coffee cup calorimeter. the metal and wateer come to the same temp. at 32.5 degree C.

A) how much heat did the metal give up to the water?

B) what is the specific heat of the metal?

C) how many grams of the metal at 80.0 degree C would have to be used to heat half as much water (100.0 g) by to the same temp.?

thanks in advance

2007-02-06 14:03:57 · 1 answers · asked by Becky 2

i was doing this project and my report is due tomorrow! i need some answers!

2007-02-06 13:57:43 · 8 answers · asked by GabiiBabii<3 1

2007-02-06 13:55:15 · 3 answers · asked by Dani G 1

Can you please list the source for where you got the information.

2007-02-06 13:52:39 · 7 answers · asked by Rimi M 1

You made 100.0 mL of a lead(II) nitrate solution for lab but forgot to cap it. The next lab session you noticed that there was only 80.0 mL left (the rest had evaporated). In addition, you forgot the initial concentration of the solution. You decide to take 2.00 mL of the solution and add an excess of a concentrated sodium chloride solution. You obtain a solid with a mass of 4.159 g. What was the concentration of the original lead(II) nitrate solution?

2007-02-06 13:44:55 · 2 answers · asked by trypanophobic34 2

looking for measurable ohm difference in water freezing.

2007-02-06 13:43:40 · 4 answers · asked by thepumpguy@sbcglobal.net 1

What is the molar mass of diazepam (Valium®) if 0.05570 mol weighs 15.86 g?

I'm stuck on this and have no clue how to start. Much help would be appreciated.

2007-02-06 13:43:33 · 2 answers · asked by DJ 1

A 1.00 g sample of an alkaline earth metal chloride is treated with excess silver nitrate. All of the chloride is recovered as 1.38 g of silver chloride. Identify the metal.

2007-02-06 13:43:02 · 1 answers · asked by trypanophobic34 2

2007-02-06 13:41:27 · 1 answers · asked by Anonymous

i just need to make sure if it's really the same..

2007-02-06 13:39:41 · 2 answers · asked by mitch 1

2007-02-06 13:26:52 · 7 answers · asked by jessica w 1

an organic reaction to make sodium acetate and ethanol from ethyl acetate with sodium hydroxide resulted in a yield of 45% of sodium acetate.
a) write the balanced chemical equation
b) determine the mole ratio for the reaction
c) determine the mass ratio for the reaction

pleace and thanks

2007-02-06 13:20:33 · 1 answers · asked by Justine 1

Hi. What is the cost/gram of tin?
And what are the good and bad points of tin?
Thanks in advance people! =]

2007-02-06 13:18:18 · 2 answers · asked by Aanchi11 2

2007-02-06 13:10:47 · 2 answers · asked by Deb or Bob S 1

i have read from internet, and know that Lineweaver-Burk Plot will suggest some inaccuracy in the determination of the Vmax and Km, but why we still use it, i think that it must have some advantage to use Lineweaver-Burk Plot. so need some one to tell me? sorry my english is not good enough.

2007-02-06 13:07:26 · 1 answers · asked by teck kim 2

Complete the equation.
Carbon 14 undergoes radioactive decay to become nitrogen- 14.

14
C-----> ? + ?+?
6

is radioactive decay an alpha or what?

2007-02-06 13:01:41 · 1 answers · asked by asif7083 2