Chemistry - January 2007

2007-01-08 07:02:07 · 4 answers · asked by Nathan C 1

With a plentiful supply of air, 3.0 parts carbon reacts with 8.0 parts oxygen to produce carbon dioxide. use this mass ratio to calculate how much carbon is required to produce 990g of carbon dioxide. the answer is 270 but how the hell this that happen?

2007-01-08 06:55:00 · 2 answers · asked by maya 4

suggest 5 clues you would consider before deciding whether a change is physical or chemical

2007-01-08 06:51:25 · 1 answers · asked by Guitr Playrrr 2

For example, to write a balanced (single replacement) equation for:

Zn + AgNO[sbscrpt3] ---> ?

I would have simply written

Zn + AgNO[sbscrpt3] ---> ZnNO[sbscrpt3] + Ag

However, the book lists the answer as


Zn + 2Ag(NO[sbscrpt3])[sbscrpt2] ---> Zn(NO[sbscrpt3])[sbscrpt2] + 2Ag

Why?

Is it because the O is diatomic, so you need to add:


Zn + AgNO[sbscrpt3] ---> Zn(NO[sbscrpt3])[SBSCRPT2 HERE] + Ag

Thus needing to add:

Zn + [COEFFICIENT 2 HERE]AgNO[sbscrpt3] ---> Zn(NO[sbscrpt3])[sbscrpt2] + Ag

And finally:

Zn + [coefficent2]AgNO[sbscrpt3] ---> Zn(NO[sbscrpt3])[sbscrpt2] + [COEFFICIENT 2 HERE]Ag


?

Also, how did the subscript 2 get added to just the (NO[sbscrpt3]) ... as in ZnNO[sbscrpt3]? I thought you couldn't add subscripts that weren't there to begin with so you'd have to make that whole part 2ZnNO[sbscrpt3], and add a 2 as the coefficent in the lone Zn on the left side of the equation?

Thanks a bunch!

2007-01-08 06:48:14 · 3 answers · asked by Anonymous

please help this project is due tommorow

2007-01-08 06:40:41 · 5 answers · asked by Anonymous

2007-01-08 06:28:07 · 5 answers · asked by scottykai 1

With a plentiful supply of air, 3.0 parts carbon reacts with 4.0 parts oxygen to produce carbon monoxide. use this mass ratio to calculate how much carbon is required to produce 990g of carbon dioxide. the answer is 270 but how the hell this that happen?

2007-01-08 06:24:49 · 4 answers · asked by maya 4

Why nylon clothes crackle when you undress? and Why you can get shock walking on nylon carpet? thank you

2007-01-08 06:11:24 · 15 answers · asked by vamy189 2

I am making a solution of DL-alpha-Glycerol Phosphate. I want it to be a 25mM solution. The Moleclar Mass is 194.36 (according to the label). I added 1.21 g of Glycerol -PO to 250 mL of water. I think this is the correct amount but the solution looks cloudy and it should be clear. Could someone let me know if I did this wrong?

2007-01-08 06:07:09 · 6 answers · asked by Anonymous

Thank you!! Please show each step as you do it!!

Ce(Io3)4+H2C2O4= Ce2(C204)3+I2+H2O+Co2

2007-01-08 05:21:01 · 1 answers · asked by laur664664 1

2007-01-08 05:09:36 · 3 answers · asked by LP 1

Is it nucleophillic, electrophillic??

2007-01-08 05:02:42 · 2 answers · asked by flycarchick 2

If the following pairs of metals and solutions of their ions were put together in a voltaic cell, which directions would the electrons flow in?

Al and Ni _______ ----> _______

Mn and Pb _______ --- > _______

Ag and Zn _______ --- > ________

Cu and Cr ________ --- > _______

Pb and Ag _________ --- > _______

2007-01-08 04:39:53 · 3 answers · asked by cetinnovations 1

Hi, I'm homeschooled, so I really have no way of figuring out what I'm doing wrong (since I have no teacher, and I've already surpassed my mother's knowledge of the subject).

Anyway, in chemistry I'm at the point of "completing and balancing combination reactions." Here's an example of a problem that I do not understand:

Be + O [sbscrpt2] ----> ? (I would have written simply BeO [sbscrpt2] because every atom on the left is also accounted for on the right, and I thought that that was all that's necessary.)

However, the book lists the answer as 2BeO. Where did the extra Be come from?

Thank you!!!

2007-01-08 04:21:40 · 6 answers · asked by Anonymous

Can you tell me which element in the compound has the positive oxidation number and which has the negative oxidation number

A.
NH3

B.
HCI

C.
NO2

D.
NaCI

E.
SO2

F.
MnO2

2007-01-08 04:02:19 · 3 answers · asked by cetinnovations 1

I've just started college, and I haven't yet decided what I want to major in. I'm currently regidtered as a Chem major, but I haven't even really decided what I want to do yet. I want to pursue a career in dentistry, and was given the option of some type of biological science (biology) or chemistry. I'm also very interested in the current research on stem cells, and such. I really want to get into the major healthcare problems of today that haven't really been perfected, such as helping people with lost limbs, dental fractures, etc. So basically I would like to know that if I do change my major to those fields, what occupations can they lead me to, what companies, and is there even a job market for them???

2007-01-08 03:27:33 · 5 answers · asked by A 3

change in entropy =change in enthalpy / temperature
From this formula ,entropy change seems to be inversely propostional related with temperature,wheras it is found that on increasing temperature,entropy of system increases.
Kindly explain the contradiction.Thanks

2007-01-08 03:05:24 · 4 answers · asked by Anonymous

Crystals are made up of anions and cations or different atoms arranged as per lattice of the crystal structure. Is the lattice only an imaginary idea or it is real. What is occupied between the inter atomic space in the lattice, the spacing can be more that the ionic radi.

2007-01-08 02:57:08 · 4 answers · asked by mandira_nk 4

2007-01-08 02:29:21 · 33 answers · asked by Fiona B 1

yeast+sugar+vinegar
yeast+sugar+backing soda

2007-01-08 02:25:29 · 3 answers · asked by germin66 1

(b) Calculate the molarity of the following solutions:

(i) 2.0 g CuSO4(s) in 100.0 cm3 water
(ii) 5.0 g Ca(OH)2 in 2 dm3 water

2007-01-08 02:22:29 · 3 answers · asked by jess_xx_2001 1

2007-01-08 02:10:46 · 5 answers · asked by becknise 2

Hi, I recently bought a gps that has a warning label california propositon 65. That the product contain cancerous material. I called that company and they said the product contained lead soldering. My question, lead dangerous when its not being physically touched by human hands, or ingested? Does lead form vapors of lead ?or deteriote forming dust of lead.

Thanks

2007-01-08 01:52:22 · 3 answers · asked by bend t 1

do you know....

2007-01-08 01:45:58 · 4 answers · asked by Anonymous

2007-01-08 01:44:12 · 2 answers · asked by Anonymous

2007-01-08 01:28:56 · 3 answers · asked by Anonymous

I am doing a coursework on this question and i dont know wot to write in the conclusion.Plz help me

2007-01-08 01:28:54 · 20 answers · asked by Sheraz.A 1

water changes to steam at boiling temperatures, but dries up on the floor at room temperatures..??

2007-01-08 01:23:03 · 2 answers · asked by shankease 2

can anyone tell me the name of the chemical listed below?

Fe - ?
CaO - ?
MgO - ?
H2SO4 - ?
HNO3 - ?
HCL - ?
NaOH - ?
KOH - ?
AgNO3 - ?
KIO - ?
NH4Cl - ?
BaCl2 - ?
HFO - ?

And 1 more question is that

what is lonic bond and coralent bond.

2007-01-08 00:42:24 · 6 answers · asked by Hua Cu P 1

Are AgHS and Al2(CO3)3 respectively named Silver hydrosulfide and dialuminum tricarbonate?

Explain why chlorine has a lower electron affinity value than sulfur, why phosphorous has a higher value than silicon, and why beryllium has a higher value than lithium.

Arrange the following atoms or ions in order of increasing size:
1.Br -, Ca 2+, K +, Se 2-
2.Al 3+, F -, Na +, Mg 2+, O 2-
3.As 3-, Ca 2+, Cl -, K +

2007-01-08 00:40:55 · 2 answers · asked by Maziar S 3