Chemistry - February 2007

plz explain them!!

2007-02-25 04:18:46 · 3 answers · asked by Anonymous

2007-02-25 04:13:14 · 2 answers · asked by erikck 2

2007-02-25 04:05:00 · 4 answers · asked by Anonymous

2007-02-25 03:50:40 · 5 answers · asked by Anonymous

2007-02-25 03:44:23 · 4 answers · asked by Anonymous

2007-02-25 03:42:41 · 8 answers · asked by Anonymous

please help me, i dont have any ideas for a good conclusion for my science fair project.

2007-02-25 03:16:58 · 2 answers · asked by Ant 1

2007-02-25 03:06:50 · 3 answers · asked by Richard A 2

2007-02-25 03:06:18 · 2 answers · asked by Richard A 2

2007-02-25 03:05:32 · 1 answers · asked by Richard A 2

2007-02-25 03:04:49 · 3 answers · asked by Richard A 2

2007-02-25 03:04:06 · 1 answers · asked by Richard A 2

2007-02-25 02:49:00 · 1 answers · asked by kim 1

what tests could be used to differentiate them?

2007-02-25 02:45:40 · 2 answers · asked by kim 1

explain how the test could differentiate them

2007-02-25 02:43:52 · 2 answers · asked by kim 1

2007-02-25 02:41:31 · 5 answers · asked by kim 1

2007-02-25 02:37:41 · 5 answers · asked by Noname 2

How many grams of phosphine (PH3) can form by the reaction of 33.0 g phosphorus and 90.0 L hydrogen gas at STP?

P4(s) + 6 H2(g) ====> 4 PH3(g)

2007-02-25 02:37:03 · 2 answers · asked by pinay804 2

please help!

2007-02-25 02:22:26 · 2 answers · asked by Anonymous

2007-02-25 02:20:40 · 2 answers · asked by suzy.k119 2

I encountered this problem on the 2004 FRQ AP exam:

(d) The standard free energy of formation, ΔG°f, of Fe2O3(s) is -740. kJ mol-1 at 298 K.

The ΔS°f is -0.28 KJ/mol/K
The ΔH°f is -824 KJ/mol

The question basically is, by how much does the ΔS°f decrease the free energy of the reaction?
And the same question goes for ΔH°f , except in this case it would be by how much does it increase the free energy of the reaction! (KJ/mol of Fe2O3)

thanks!

2007-02-25 02:20:18 · 4 answers · asked by Anonymous

I have heard of a product called Pyrogen and its an alternative to Halon. Is it better than Halon and commercially more marketable?
And which country is Pyrogen manufactured?

2007-02-25 02:12:12 · 1 answers · asked by chan_mun_keng 1

Nitrogen dioxide has opposing roles in our world. It is essential in the industrial production of nitric acid, but is also a contributor to acid rain and photochemical smog. Calculate the volume of nitrogen dioxide produced at 741 torr and 28.2°C by the reaction of 4.97 cm3 of copper (d = 8.95 g/cm3) with 230.0 mL of nitric acid (d = 1.42 g/cm3, 68.0% HNO3 by mass).

Cu(s) + 4 HNO3(aq) ===> Cu(NO3)2(aq) + 2 NO2(g) + 2 H2O(l)

2007-02-25 02:11:01 · 3 answers · asked by pinay804 2

2007-02-25 02:07:15 · 1 answers · asked by Anonymous

I know cobalt can be used to color glass, vases and other things, but i need to explain how it's capable to color them, lol i've looked around but havent been able to explain it if you know a web site other than webelements.com it would be greatly appreciated

2007-02-25 02:03:56 · 2 answers · asked by horsecrazygal01 2

Are each of Sodium benzoate, Benzoic acid, Resorcinol, Anthracene soluble in each of H2O, CH3COCH3, Toluene, CCL4, Ethanol in the cold condition or with heat ( are they moderate soluble or sparingly soluble in the case of heat?).
please write if it is soluble with heat or in the cold state.

2007-02-25 02:02:13 · 2 answers · asked by Moamen 1

2007-02-25 02:00:36 · 3 answers · asked by francis 1

2007-02-25 01:53:11 · 2 answers · asked by onyx 2

in CCl4(carbon tetra chloride) , carbon is only 4.05% but it is a organic compound. why?

2007-02-25 01:39:36 · 13 answers · asked by shakti s 1

Why are Van der Waals forces (London forces) weaker than ionic, covalent, and metallic bonds?

2007-02-25 01:38:14 · 2 answers · asked by untilyoucamealong04 3