Chemistry - November 2006

For a chemistry homework question

2006-11-29 04:19:29 · 1 answers · asked by Anonymous

I've been given the task:
'Hydrogenated oil has molecules that don't have kinks in them. Draw and label diagrams to show how this means they will solidify more easily.'
Help! I really don't understand

2006-11-29 04:17:53 · 2 answers · asked by Anonymous

Dry air is approximately 78% nigtogen, 21% oxygen and 1% argon, by number of molecules. What is the partial pressure of oxygen in a sample of dry air, if atmospheric pressure is 751 torr?

2006-11-29 04:09:34 · 1 answers · asked by lucid_dreams6 1

Freon-12 CF2Cl2 has been widely used in air conditiong systems, is consisdered a threat to the ozone layer in the stratosphere. Calculate the root-mean-square velocity of Freon-12 molecules in the lower stratosphere where the temp is -65 degrees C.

2006-11-29 04:08:03 · 2 answers · asked by lucid_dreams6 1

in the presence of an appropriate catalyst, both gases add hydrogen. the hydrogenated products are identified their molecular weight is 58. which of the structures below can be eliminated by this information?
1. trans but-2-ene
2. cis but-2-ene
3. but-1-ene
4. 2-methylpropene

2006-11-29 04:07:18 · 4 answers · asked by (: 2

- What are the effects of each chemical?
- to the surrounding plant life
- to the surrounding animal life
- to the surrounding environment
- land, air and water supply
- to the surrounding human population
- health concerns

2006-11-29 03:58:36 · 2 answers · asked by Anonymous

science

2006-11-29 03:28:57 · 3 answers · asked by Marcus B 1

I am having problems balancing this
KI+HNO3=KNO3+NO+I2+H2O

2006-11-29 03:05:45 · 5 answers · asked by steven11111958 1

2006-11-29 02:54:20 · 8 answers · asked by Anonymous

science homework

2006-11-29 02:43:28 · 6 answers · asked by yipee! 1

2006-11-29 02:37:28 · 4 answers · asked by chemist and chemista 1

2006-11-29 02:34:25 · 7 answers · asked by Anonymous

I don't want to use chemical hair straighteners but natural products don't work for me. Is there something to fix the root that causes the hair curl in the first place and make it grow straight in the future?

Hopefully someone in chemistry will have the answer for me.

2006-11-29 02:29:53 · 2 answers · asked by Anonymous

A mixture contained no flourine compound except methyl fluoroacetate, FCH2COOCH3 (molar mass- 92.1 g/mol). When chemically treated, all the flourine was converted to CaF2 (molar mass= 78.1 g/mol) The mass of CaF2 obtained was 32.4 g. Find the mass of methyl fluoroacetate in the original mixture.

2006-11-29 02:27:56 · 2 answers · asked by Kenneth B 1

Which one of the following reagents is capable of transforming Cu2+(1 M) to Cu(s)?

a) I– (1 M)
b) Ni(s)
c) Al3+(1 M)
d) F– (1 M)
e) Ag(s)

I think its B, Nickel...can anyone confirm this?

2006-11-29 02:11:03 · 2 answers · asked by Erin C 1

All the procedures tell that we must use drying agent in the solvent to remove water. But why it is so important? I evaporate all my solvent then I put my extract in solution with methanol and then measure concentration. I could understand that impurities in water could affect my experiment if I'd take the mass of my extract but, in my case, only the concentration of a compound X.

Thanks

2006-11-29 01:55:23 · 2 answers · asked by Anonymous

How many coulombs of electrical charge must pass through an electrolytic cell to reduce 0.82 moles of Ca2+ ion to calcium metal?

a) 3.9e3
b) 1.6e5
c) 7.9e4
d) 4.2e–6
e) 4.0e4

I got b, 96500 x 2 = 193000 x .82 = 158260 ...im not sure Im doing this right...

2006-11-29 01:41:28 · 1 answers · asked by Erin C 1

nothing

2006-11-29 01:21:36 · 13 answers · asked by Ganesh A 1

2006-11-29 01:07:25 · 4 answers · asked by sally 1

I was trying to figure out if the bond angles in NF3 are larger than in NH3. My reasoning led me to the conclusion that they should be larger, though in reality the opposite is true (102 deg for NF3 and 106 deg for NH3). I can't pinpoint where I am mistaken.

Here is my reasoning:
According to VSEPR the repulsion for lone pair-bond e (electrons) is greater than bond e- bond e. Thus the bond angles will be determined by the strength of the lone-pair-bond e repulsion. F is more electronegative, thus it will pull closer to it the bond electrons, reduce the electron cloud density near N, reduce the repulsion lone-pair-bond e, thus decrease the lone pair-bond e angle and increase the bond e- bond e angle.

What am I missing?

2006-11-29 00:55:40 · 3 answers · asked by bellerophon 6

what are the charecteristic that caused wood ash important to be made soap and claen the oil-stain?

2006-11-29 00:30:33 · 2 answers · asked by acid_burn 1

A) If the valence atomic orbital of an atom are sp hybridized, how many unhybridized p orbitals remain in the valence shell? How many pi bonds can the atom form?

B) How many sigma and pi bonds are generally part of a triple bond?

C) How do multiple bonds introduce ridigity into molecules?

2006-11-28 22:30:40 · 4 answers · asked by pinkpanthergirl 1

For statements a) through d) use the reaction:


SiCl4(l) + 2Mg(s) --> 2MgCl2(s) + Si(s)



a) Mg is the oxidizing agent

b) SiCl4 is the oxidizing agent

c) Mg is reduced

d) SiCl4 (or Si in SiCl4) is reduced

e) HCl(g) + NH3(g) --> NH4Cl(s) is a redox reaction

f) O3(g)(aq) + NO(g) --> O2(g) + NO2(g) is a redox reaction

2006-11-28 22:29:54 · 2 answers · asked by Whatever 1

For the reaction BaCl2 (aq) + ZnSO4 (aq) BaSO4 precipitates out.
Calculate the percent yield (%) if 16.775 g of BaSO4 precipitates
when 2.100 L of 0.0500 M BaCl2 (aq) and 1.920 L of 0.0456 M ZnSO4 (aq) are mixed.

2006-11-28 22:29:18 · 1 answers · asked by Whatever 1

A student prepares a solution by dissolving 5.98 g of KOH in enough water to make 250. mL of solution.
The student then transfers 27.0 mL of this solution into a 100. mL volumetric flask. Water is then added
up to the 100. mL mark.

2006-11-28 22:28:23 · 1 answers · asked by Whatever 1

2006-11-28 22:27:23 · 2 answers · asked by allornothindc 1

Aqueous solution of X is an acidic solution. As a chemistry student, describe briefly how you are able to prove that X is an acidic solution. You're not allow to use litmus paper, pH meter or any indicators.

2006-11-28 22:00:20 · 2 answers · asked by colzgirl 2

I would like to know frankincence oil distillition specialy boswelia carteri and boswelia fereana how much oil can distill per kilo.I willappreciate your information.
Thank you

2006-11-28 21:34:08 · 1 answers · asked by abdulahi g 1

When Barium Carbonate is heated strongly, it decomposes to give carbon dioxide and barium oxide.

BaCO3(s) --> BaO(s) + CO2 (g)

What is the volume of carbon dioxide produced at r.t.p when 78.8g of barium carbonate is heated?
[Relative molecular mass of barium carbonate is 197]

2006-11-28 20:52:37 · 3 answers · asked by missjolintan 3

2006-11-28 20:31:06 · 2 answers · asked by letsbeserious 1