Chemistry - November 2006

2006-11-24 04:52:49 · 13 answers · asked by FEDERITO T 1

Also if possible what is the most common charge (oxidation number) for Antimony?

2006-11-24 04:50:41 · 4 answers · asked by Anonymous

2006-11-24 04:43:58 · 6 answers · asked by Dan L 1

2006-11-24 04:39:24 · 6 answers · asked by Brenda T 1

Write the reactions for the Standard heat of formation of these from their elements in the standard state:

a)HNO3(l)
b) Ca(NO3)2(l)
c) NaOH (s)
d) H2O(l)


Can anyone please verify the following answers...

a) 1/2 H2(g) + 1/2 N2(g) + 3/2 O2(g) -----> HNO3(l)

b) Ca(s) + N2(g) + 3O2(g) -----> Ca(NO3)2(l)

c) Na(s) + 1/2 O2(g) + 1/2 H2(g) -----> NaOH(s)

d) H2(g) + 1/2 Os(g) -----> H2O(l)

2006-11-24 04:08:12 · 2 answers · asked by smithwss 2

nitro-cellulose based

2006-11-24 04:05:18 · 2 answers · asked by rajusahajwan 1

A sample of hydrogen gas was collected over water at 21 degrees C and 685 mm Hg. The Volume of the container was 7.80 L. Calculate the mass of H2(g) collected.

(Vapor pressure of water at 21 degreesC is 18.6 mm Hg)


Can anyone please verify that the answer is n=PV/RT where.......

P = (685-18.9)/760 = .877 atm
V = 7.80 L
R = .0821 L*atm/Mol *K
T = 21+273.15 = 294.15

(.877(7.80) / .0821(294.15) =.283 mol H2 = .283(2) = .566 g H2

2006-11-24 03:59:30 · 2 answers · asked by smithwss 2

how it appiares

2006-11-24 03:54:46 · 6 answers · asked by Anonymous

2006-11-24 03:53:38 · 2 answers · asked by wlf_a 3

err...randomly boring question but does anyone know ANYTHING about fractional distillation?!

2006-11-24 03:48:25 · 8 answers · asked by Anonymous

Ethanol undergoes combustion according to the equation

C2H5OH(l) + O2(g) ----------> CO2(g) + H2O(l)

The of ethanol, C2H5OH(l), is -1366.8 kJ/mol. Given
that:
deltaHf [CO2(g)] = -393.5 kJ/mol
deltaHf [H2O(l)] = -285.8 kJ/mol

What is the standard enthalpy of formation of ethanol ?

2006-11-24 03:47:50 · 2 answers · asked by smithwss 2

(thanks bonhommecretienne...but need a more complete answer)

A 100mL sample of 0.200 M aqueous hydrochloric acid is added to 100 mL 0f 0.200 M aqueous ammonia in a calorimeter whose heat capacity is 480 J/degreesC. The following reaction occurs when the two solutions are mixed.

HCl (aq) + NH3(aq) ---------> NH4Cl (aq)

The temperature increase is 2.34 degreesC. Calculate deltaH of neutralization per mole of HCl and NH3 reacted. Assume the densities and the specific heat are the same as for the water. (1.00 g/mL and 4.184 J/g degreesC respectively)

2006-11-24 03:43:26 · 2 answers · asked by smithwss 2

Having trouble trying to solve this chem homework question. Its pretty difficult to solve.

If all the H20(g) in the atmosphere (assume it is 1% by volume) suddenly condensed to H20(l), and all the enthaply of this process was captured and converted to electrical energy, how long would this energy power an average size city of 1 million?

I know that atmospheric water vapor volume is 12.9 cubic kilometers, but cant figure out the rest.

2006-11-24 03:40:48 · 2 answers · asked by Anonymous

2006-11-24 03:36:53 · 5 answers · asked by JESSE H 1

When 1.75g of CaCl2 dissolves in 125g of water in a coffee-cup calorimeter, the temperature increases by 2.44 degrees celsius. What is the heat change per mole of CaCl2 dissolved in water? Assume that all of the heat is absorbed by the water (c=4.18j/g deg C)

2006-11-24 03:33:30 · 3 answers · asked by Anonymous

2006-11-24 03:32:10 · 1 answers · asked by JESSE H 1

a) forms four bonds
b) bond to oxygen
c) bond to nitrogen
d) bond to carbon

2006-11-24 03:29:00 · 8 answers · asked by Lindsay A 1

a) aromatic compounds
b) heterocyclic compounds
c) hetergeneous compounds
d) perfluoro compounds

2006-11-24 03:27:38 · 6 answers · asked by Lindsay A 1

2006-11-24 03:26:13 · 6 answers · asked by Lindsay A 1

When 2.50g of potassium bromide dissolves in 1.00102g water in a calorimeter, the temperature drops from 22.657 degees celsius to 21.661 degrees celsius. What is the heat change per gram of potassium bromide dissolved in water? Assume that al the heat comes from the water (c= 4.18J/g deg C)

2006-11-24 03:25:28 · 1 answers · asked by Anonymous

2006-11-24 03:24:32 · 3 answers · asked by Lindsay A 1

pls kindly give reasons for your answers. thanks alot..

2006-11-24 03:21:34 · 3 answers · asked by Anonymous

2006-11-24 03:04:56 · 9 answers · asked by princess 1

?????????????????TELLL ME SOOONNNN

2006-11-24 02:50:53 · 1 answers · asked by Anonymous

I need a siple thing that water reacts to. I am doing scinece and it says I gotta determine the identity of unknown substances. Water is one of them. So what does it react with so I can know the difference between it and Rubbing alchohol, viengar, and salt water. Also if you know what those react with that would help. They can't react with the same things, like venegar can't react with whatever I use for water because then I wouldn't know the difference.

2006-11-24 02:01:58 · 5 answers · asked by torirowe 2

2006-11-24 02:01:17 · 1 answers · asked by KIATOU 1

i know there is 20 altogether, but is it 10 or 11 essential?

2006-11-24 01:34:22 · 4 answers · asked by Anonymous

2006-11-24 01:34:04 · 6 answers · asked by styce 4

Consider the following unbalanced equation
Ca3(PO4)2(s) + H2SO4(aq)------> CaSO4(s) + H3PO4(aq)

What masses of calcium sulfate and phosphoric acid can be produced from the reaction of 1.0 kg calcium phosphate with 1.0 kg concentrated sulfuric acid (98% H2SO4 by mass)?

2006-11-24 01:25:07 · 2 answers · asked by Catherine D 1

do you set the limiting reagent equal to 1, or the reagent in excess?

2006-11-24 01:20:01 · 2 answers · asked by Anonymous