Chemistry - October 2007

i am planning to buy a microscopes.plz answer.i want good websites

2007-10-06 03:28:59 · 1 answers · asked by rampageenergyman 2

will it .i want to see rusted iron.plz tell

2007-10-06 03:25:46 · 1 answers · asked by rampageenergyman 2

2007-10-06 03:21:45 · 2 answers · asked by Anonymous

calculate the total heat (J) needed to convert 0.316 mol ethanol gas (C2H6O) at 151°C and 1 atm to liquid ethanol at 25.0°C and 1 atm.

Boiling point at 1 atm 78.5°C
cgas 1.43 J/g·°C
cliquid 2.45 J/g·°C
H°vap 40.5 kJ/mol

2007-10-06 02:58:18 · 1 answers · asked by Ecka 1

2007-10-06 02:43:52 · 2 answers · asked by Dr. An 1

4 Write balanced chemical equations or formulas (annotated where appropriate) for each of the following descriptions:

(i) oxygen undergoes photodissociation in the upper atmosphere;

(ii) the nitric oxide molecule undergoes photoionisation in the upper atmosphere;

(iii) ozone is formed in the upper atmosphere;

(iv) ozone is destroyed in the upper atmosphere;

(v) nitric oxide catalyses the decomposition of ozone in the stratosphere;

(vi) nitrogen dioxide is an acidic oxide and forms an acid solution in water;

(vii) sulfur dioxide emissions from industrial sources cause acid rain;

(viii) why rainwater is naturally acidic, even in the absence of any polluting gases

(ix) despite the answer in (viii), why the pH of unpolluted sea water is about 8.2

(x) why nitrogen is not, but carbon dioxide is, a 'greenhouse gas'

2007-10-06 02:26:28 · 1 answers · asked by Hammad A 1

2007-10-06 02:21:22 · 1 answers · asked by Kathy Phan 1

a)
Compounds containing triply bonded silicon, Si≡Si, cannot be made under normal circumstances, but the corresponding carbon compounds (the alkynes) are common. Explain why this is so.

b)
Give an explanation for the fact that SF6 exists and is stable, but OF6 is unknown.

c)
Write a structural formula for two different isomers of [Co(H2O)2(en)2]Cl2. Indicate the oxidation state of the Co in each case.

2007-10-06 01:44:27 · 2 answers · asked by Hammad A 1

2007-10-06 01:18:08 · 2 answers · asked by Preethikrish 1

2007-10-06 00:31:34 · 2 answers · asked by Eman S 1

2007-10-05 20:53:25 · 8 answers · asked by smr_bd10 1

2007-10-05 17:42:28 · 1 answers · asked by Dr. An 1

What's the molar heat capacity of ethanol, C2H5OH(l)?
* The specific heat of ehtanol is 2.46 J/g℃

I think the question is wrong because the unit of specific heat is J/g, isn't it?? and J/g℃ is for specific heat capacity? so, when you're solving, change the unit if it needs to be changed.

2007-10-05 17:02:34 · 2 answers · asked by ? 2

2007-10-05 16:44:33 · 9 answers · asked by ixat02 2

2007-10-05 16:32:02 · 3 answers · asked by Anonymous

What is the theoretical yield for this reaction?

2007-10-05 16:03:04 · 2 answers · asked by Anonymous

Ibuprofen has formula C13H18O2

a) how many atoms of carbon are in .425g

.425g(1moleC/12.01gC)(6.022 x 10^23 atoms of C/1 moleC)= 2.13 x 10^23atoms of carbon

b) how many grams of H are in 3.75 x 10^22 molecules of Ibuprofen
3.75 x 10^23 molecules (1 mole of Ibuprofen/6.022x10^23 atoms of Ibuprofen) (18 moles of H/1 mole of Ibuprofen) (1.008g H/1 mole H)

are those right?

2007-10-05 15:40:06 · 1 answers · asked by shirah d 2

which of the following solutions is the most basic?
a.) 0.5 M NH3
b.) 0.1 M KOH
c.) 0.1 M Ca(OH)2

i think that both b & c are strong bases, but i dont know how to compare them. also, i kow that nh3 is a weak base, but does concentration have anything to do with it?? i dont get this problem?
thanks for any help
ps- i should be out at a dumb party getting wasted but im here doing ap chem. you want my life.

2007-10-05 15:30:04 · 3 answers · asked by Anonymous

The element chromium has four naturally occurring isotopes. Use the relative abundance of each to calculate the average atomic mass of chromium.

Cr = 4.34%, Cr = 83.79%, Cr = 9.50%, Cr = 2.37%.

im not sure how i would do this without being given the masses! any help?

2007-10-05 15:28:45 · 3 answers · asked by nikki 2

2007-10-05 15:28:33 · 2 answers · asked by anrtech 1

How are fossil fuels formed?

2007-10-05 14:29:14 · 1 answers · asked by james h 2

Describe simple chemical tests that would enable you to distinguish between the following sets of compounds. Write equations for any chemical reactions:

(a) dinitrogen monoxide (nitrous oxide), ammonia, and nitrogen

(b) carbon monoxide, carbon dioxide, and nitrogen monoxide

(c) dilute hydrochloric acid, deuterium oxide, and hydrogen peroxide solution

2007-10-05 13:48:16 · 1 answers · asked by Hammad A 1

Write balanced chemical equations or formulas (annotated where appropriate) for each of the following descriptions:

(i) oxygen undergoes photodissociation in the upper atmosphere;

(ii) the nitric oxide molecule undergoes photoionisation in the upper atmosphere;

(iii) ozone is formed in the upper atmosphere;

(iv) ozone is destroyed in the upper atmosphere;

(v) nitric oxide catalyses the decomposition of ozone in the stratosphere;

(vi) nitrogen dioxide is an acidic oxide and forms an acid solution in water;

(vii) sulfur dioxide emissions from industrial sources cause acid rain;

(viii) why rainwater is naturally acidic, even in the absence of any polluting gases

(ix) despite the answer in (viii), why the pH of unpolluted sea water is about 8.2

(x) why nitrogen is not, but carbon dioxide is, a 'greenhouse gas'

2007-10-05 13:44:32 · 1 answers · asked by Hammad A 1

Could you please show me step by step your result.

2007-10-05 12:59:00 · 3 answers · asked by xxxladyxxx 1

Please explain the reaction(s) that take(s) place

2007-10-05 12:42:02 · 3 answers · asked by Chris D 1

Some fluorescents that contain high levels of mercury I understand but I need specifics and I'm having little luck aside from how to recycle them but that doesn't apply.

2007-10-05 12:32:03 · 2 answers · asked by Anonymous

What is it usually used for??
Is it illegal?

2007-10-05 12:14:53 · 1 answers · asked by Dancing girl.[: 2

2007-10-05 12:10:49 · 3 answers · asked by Anonymous

are the following solutions undersaturated, saturated, or oversaturated?

1. 20 grams of NaCl/100 grams of water at 20ºC.


2. 100 grams of glucose/100 grams H2O at 20ºC.


3. 100 grams of Na3PO4/100 grams of water at 80ºC.

2007-10-05 12:07:03 · 2 answers · asked by blueeyegreen 1

My science teacher made us do an experiment where we added liver to hydrogen peroxide. Now I have to figure out a way to capture the Oxygen put off by the chemical reaction. I don't actually have capture the gas just say how I would... There are no limits in materials but I have to capture PURE oxygen (no air) and cannot use a balloon! PLEASE HELP ME SCIENTISTS AND OTHER SMART PEOPLE!!!!

2007-10-05 11:59:11 · 3 answers · asked by Anonymous