Chemistry - March 2007

2007-03-17 05:55:26 · 2 answers · asked by Anonymous

2007-03-17 05:42:01 · 2 answers · asked by Mindy D 2

Explain these observations??? PLEASE HELP I CANT DO THIS I AM SO STUCK!!!! Thank you xXx

2007-03-17 05:40:03 · 2 answers · asked by gem--b 1

1. what is the phase of MgN?

2. A volatile liquid was found to have the composition 62.04% carbon, 10.41% Hydrogen, and 27.55 Oxygen by mass. At 100 degree celsius and 1.00atm, 440.ml of the gaseous compound had a mass of 1.673g. the empirical formula is C3H6O.

Calculate the molar mass of the compound
Determine the molecular formula of the compound.

3. CaCO3(s)-> CaO(s)+CO2(g)

When 1.000g of the impure limestone was heated to constant mass, 215mL of gas were evolved at 25 degree celsius and a pressure of 755mmHg. What was the mass percent of the CaCO3.

2007-03-17 05:30:05 · 2 answers · asked by Preeya 5

The structures of two compounds and the measured approximate ratio of 1H-NMR spectrum signal areas for one of the compounds are shown

Which compound was responsible for the 1H-NMR spectrum?


Ratio of 1H-NMR spectrum signal areas = 40:40:20
fluoro-benzene.
or
hexane

2007-03-17 05:19:29 · 2 answers · asked by lukeappleboy 1

When a 5.00 g sample of solid ammonium nitrate dissolves in 60.0 g of water in a coffee-cup calorimeter (Figure 5.18), the temperature drops from 22.0°C to 17.0°C. Calculate H (in kJ/mol NH4NO3) for the solution process shown below. Assume that the specific heat of the solution is the same as that of pure water.

NH4NO3(s) ------> NH4+(aq) + NO3-(aq)

∆H =_______kJ/mol

note: this is an endothermic reaction

2007-03-17 05:18:21 · 1 answers · asked by Ham Wallet 1

Okay, if anyone could point me out to a website with these chemical equations or tell me what they are, I would really appreciate it...I have them answered, but I seriously doubt they're right and this is worth some major points.

1 - A synthesis reaction that is happening in your body.
2 - A decompostion reaction that is happening in your body.
3 - A replacement reaction happening in your body.
4 - A combustion react happening in your body.
5 - List some catalysts being used in reactions in the body.
6 - Given their location on the Activity Series, why have platinum, gold, and silver become so valuable?
7 - Why is it necessary for humans that calcium carbonate is not water soluble?

2007-03-17 05:09:28 · 4 answers · asked by Anonymous

H2SO4 + Fe(OH)3 ----> Fe2(SO4)3 + H2O

2007-03-17 04:55:08 · 5 answers · asked by Anonymous

H2SO4 + FE(OH)3 ----> FE2(SO4)3 + H2O

2007-03-17 04:54:19 · 2 answers · asked by Anonymous

Many cigarette lighters contain liquid butane, C4H10(l). Using enthalpies of formation, calculate the quantity of heat produced when 3.7 g of butane is completely combusted in air.

=______kJ

2007-03-17 04:46:57 · 2 answers · asked by Ham Wallet 1

a solution containing 2g of sodium sulfite reacts with 7 mL of phosphoric acid (H3PO4). the concentration of the acid solution is that there are 1.83g of H3PO4 per mL of solution.

a) Determine the mass of the excess reactant remaning at completion.
b) grams of water produced
c) Moles of sodium phosphate produced.
d) grams of sulfur dioxide produced.

Please explain how u get the answer.

2007-03-17 04:28:50 · 1 answers · asked by yassem1ne 2

Select the compound with the stronger acidity.



(CH3)3COH or (CH3)2CHOH


H2O or CH3CH2OH


HCl or CH3CH2OH

2007-03-17 04:20:17 · 4 answers · asked by Anonymous

2007-03-17 04:17:24 · 2 answers · asked by calculushelp1990 1

2007-03-17 03:51:10 · 5 answers · asked by Anonymous

Which of the following solutions result in a buffer ?



a) 0.050 L of 0.250 M NH3 + 0.100 L of 0.250 M HCl


b) 0.100 L of 0.250 M NH4Cl + 0.050 L of 0.025 M HCl


c) 0.100 L of 0.250 M NH4Cl + 0.050 L of 0.250 M NaOH


d) 0.100 L of 0.250 M NH4Cl + 0.150 L of 0.250 M NaOH

2007-03-17 03:49:12 · 2 answers · asked by Foxychick 1

Calculate the pH of a mixture containing equal volumes of
0.520 M NH4Cl ( use Ka = 5.60 x 10 -10 ) and 0.520 M NH3.

2007-03-17 03:48:35 · 2 answers · asked by Foxychick 1

2007-03-17 03:43:38 · 2 answers · asked by Anonymous

a solution containing2-g of sodium sulfite reacts with 7 mL of phosphoric acid (H3PO4). the concentration of the acid solution is that there are 1.83g of H3PO4 per mL of solution.

a) Determine the mass of the excess reactant remaning at completion.
b) grams of water produced
c) Moles of sodium phosphate produced.
d) grams of sulfur dioxide produced.

Please explain how u get the answer.

2007-03-17 03:41:54 · 1 answers · asked by yassem1ne 2

2007-03-17 03:26:22 · 3 answers · asked by tia 1

2007-03-17 03:20:39 · 7 answers · asked by tia 1

i got white compound for analysis.But unfortunately i didnt get time to do all the tests.but i narrowed it two,Ammonium carbonate and magnesium nitrate.It has got a really pungent smell which makes it probably ammonium carbonate but on the other hand it caused shortness in breathing for a while after inhalation so it could be ,magnesium nitrate ,so please help me.

2007-03-17 03:20:32 · 1 answers · asked by Anonymous

If I have 5% w/v of a solution of silver nitrate and I use 12 cm3 of it, how do I work out how many moles I have used? I'd like to know the method, rather than the answer please!

Help is greatly appreciated :)

2007-03-17 02:26:13 · 4 answers · asked by Lefs 1

2007-03-17 02:18:25 · 5 answers · asked by henry f 2

2007-03-17 01:24:29 · 4 answers · asked by Anonymous

2007-03-17 01:05:45 · 2 answers · asked by bubblegum39 2

What is Mendius reduction ?

2007-03-17 00:29:34 · 1 answers · asked by Rajchem 2

2007-03-17 00:12:29 · 1 answers · asked by Evelyn 1

i know that this reaction is so fast but is there any reference tell me what exactly it is? please tell me the reference.

2007-03-16 23:54:22 · 2 answers · asked by armin 2

2007-03-16 23:43:27 · 8 answers · asked by Paolo Ian L 1

?????

2007-03-16 23:19:12 · 4 answers · asked by yuki 2