Chemistry - September 2007

A natural product has the molecular formula C23H27O7.

How many oxygen atoms are in 2.92 picograms of this compound?

2007-09-30 10:24:03 · 1 answers · asked by Anonymous

a) one daughter molecule contains both parent strands and one daughter molecule contains both newly synthesized strands

b) each daughter molecule contains one parent strand and one newly synthesized strand

c) each daughter molecule contains two newly synthesized strands

d) each daughter molecule contains both parent strands

2007-09-30 09:50:45 · 2 answers · asked by dale b 1

2007-09-30 09:45:37 · 2 answers · asked by noyb 1

What is the rationale?

2007-09-30 09:44:26 · 1 answers · asked by noyb 1

If it is, where is it found? Isn't it usually mixed with things?

2007-09-30 09:34:58 · 3 answers · asked by Anonymous

h^8k^3 times 5h

2007-09-30 08:58:41 · 1 answers · asked by Anonymous

2007-09-30 08:58:05 · 1 answers · asked by hog b 6

2007-09-30 08:51:02 · 2 answers · asked by rmhayden_89 1

how would the properties of density, mass, and volume tend to change with temperature?

2007-09-30 08:48:36 · 3 answers · asked by nate121 1

2007-09-30 08:43:23 · 1 answers · asked by Asa 1

2007-09-30 08:39:31 · 7 answers · asked by nutashuh. 1

2007-09-30 08:10:50 · 2 answers · asked by jen k 1

a) carboxylic acids and alcohols
b) carboxylic acids and amines
c) aldehydes and alcohols
d) amines and alcohols

2007-09-30 07:54:26 · 2 answers · asked by Tonnie 1

I had a lab yesterday that involved dumping some copper chloride in water, observing the temp before stirring and stir. then it says add a piece of aluminum that was in a loose ball shape WITHOUT STIRRING. can someone please explain what happens when these things are done? i had lab partners that just dumped everything together and stirred everything the whole time, they finished the lab in about 5 mins with the thermometer out of the beaker half of the time so i don't know what went on and neither did they (not surprisingly)

2007-09-30 07:45:01 · 1 answers · asked by rick 2

A) aldehyde
B) ester
C) acid anhydride
D) alkene

2007-09-30 07:41:08 · 3 answers · asked by Tonnie 1

A 4.50 L sample of gas at 28 °C and 1.00 atm is changed to 0 °C and 850 torr. What is its new volume?

2007-09-30 07:40:03 · 1 answers · asked by hey there! 1

How does CH3(CH2)2COOH dissociate in water? What is the cation and anion?

What does CH3CH2NH2 + H20 yield?

2007-09-30 07:32:30 · 2 answers · asked by unknownanonymous999 2

The temp. of the gas in an aerosol container is 0 degrees Celsius (273 K). To what temp. must this gas be rasied to increase the average kinetic energy of the gas molecules by a factor of three?

2007-09-30 07:03:46 · 2 answers · asked by Anonymous

The first step in identifying an unknown sample, we need to determine the empirical formula from percent composition. For an organic compound containing only C, H and O, the laboratory sent these results:
C 40.00 % H 6.71 % O 53.29 %


The next step is to determine the molecular formula from mass spectrum. The laboratory sent these results:
formula weight was found between 118.10 and 123.10

2007-09-30 06:49:20 · 1 answers · asked by Anonymous

2007-09-30 06:40:18 · 2 answers · asked by biakk91 1

Find the Density of the water.


Density = Mass/Volume

Here is some information you will need. The data has been collected for you.

Item Mass
Empty graduated cylinder 41.6 grams
Graduated cylinder containing 82 ml of water 123.1 grams
Mass of the water ? grams
Density of the water ? g/mL

What was the density of the water in g/mL

2007-09-30 06:20:37 · 4 answers · asked by Anonymous

2007-09-30 05:34:28 · 3 answers · asked by ? 5

1. A mixture of helium and neon gases is collected over water at 28.0 °C and 745 mmHg. If the partial pressure of helium is 368 mmHg, what is the partial pressure of neon? (Vapor pressure of water at 28 °C = 28.3 mmHg.)


Dry air near sea level has the following composition by volume: N2, 78.08 percent; O2, 20.94 percent; Ar, 0.93 percent; CO2, 0.05 percent. The atmospheric pressure is 1.00 atm.


Calculate the partial pressure of each gas in atm.
a Partial pressures: N2 =0.781 atm; O2 = 0.209 atm; Ar = 9.3 × 10-3 atm; CO2 = 5 × 10-4 atm
b Partial pressures: N2 =78.1 atm; O2 = 20.9 atm; Ar = 0.93 atm; CO2 = 0.05 atm
c Partial pressures: N2 =78.1 atm; O2 = 20.9 atm; Ar = 9.3 × 10-3 atm; CO2 = 5 × 10-4 atm
d Partial pressures: N2 =0.0781 atm; O2 = 0.0209 atm; Ar = 9.3 × 10-4 atm; CO2 = 5 × 10-5 atm

2007-09-30 04:58:24 · 1 answers · asked by PiNk-PrInCeSs 3

Hi. for std'zation of Na2S2O3, KIO3 primary std was used. but i just dont get it why KI is added. and also H2SO4. please explain why? and also specifically, in the experiment we added the acid before the KI. why? and the effect if KI is added first? (in other websites i read that some added KI first...its so confusing)

2007-09-30 04:56:56 · 3 answers · asked by benjediman 2

Write the molecular equation for the reaction of solid barium carbonate and hydrogen bromide in aqueous solution. Add phase labels. Also, write the net ionic equation adding phase labels.

2007-09-30 04:53:18 · 1 answers · asked by Joe C. 1

2007-09-30 04:13:32 · 1 answers · asked by miha 1

What type of reaction is is when

aq + g = aq ?

2007-09-30 02:55:49 · 4 answers · asked by Perry 4

2007-09-30 00:18:55 · 3 answers · asked by Anonymous

1. dimethyl ketone
2 isopropyl alcohol
3. aluminum potassium sulfate
4. acetylsaloicylic acid
5. sodium bicarbonate
6. sodium hydroxide
7. sodium nitrate
8. carbon crystal
9. ascorbic acid
10. sucrose

2007-09-29 23:59:57 · 3 answers · asked by chocolate :) 4

A sample of cadmium weighing 3.512 g is dissolved in 3.00 M HCl.

Cd(s) + 2HCl(aq) -> H2(g) + CdCl2(aq)

This is the equation. I know that we need to use ratios...but i'm still not sure where to start. It would be really nice if someone can explaine to me how to do this equation and not just GIVE me the answer. Thank you everyone for your time.

Ciao.

2007-09-29 22:42:25 · 3 answers · asked by Anonymous