Chemistry - January 2007

2007-01-31 23:56:25 · 3 answers · asked by Booyah! 3

Is glycerine poisonous?
If you swallow a drop of glycerine will it have effects on you?

2007-01-31 23:50:50 · 7 answers · asked by Artemis 2

2007-01-31 23:25:36 · 3 answers · asked by Chocolate Strawberries. 4

2007-01-31 23:12:47 · 3 answers · asked by kkp 1

2007-01-31 22:58:27 · 7 answers · asked by Karlos 1

2007-01-31 20:20:09 · 3 answers · asked by amazing_sweet_angel 1

When you titrate the two reactants together and the end point is almost reached, the yellow/green solution will turn darker each time you drop KMnO4 into the flask. So, what is the colour of the end point of KMnO4? The first drop when the colour changes distinctively is a bit of like orange and pink and the second drop is darker in colour nearer to pink. So, what's the actual end point? The first or the second drop?

2007-01-31 19:27:19 · 2 answers · asked by Gaara of the Sand 3

chem 1151

2007-01-31 18:41:27 · 4 answers · asked by ishika65 1

chemistry 1151

2007-01-31 18:33:11 · 2 answers · asked by ishika65 1

2007-01-31 18:12:53 · 10 answers · asked by Anonymous

I found one process by which I can get conc of ferrous sulfate heptahydrate but i dont know the source can anyone tell me about it in detail.
Process :Dissolve about 1 g of the sample, accurately weighed, in a mixture of 25 ml of 2 N sulfuric acid and 25 ml of recently boiled and cooled water. Add orthophenanthroline TS, and immediately titrate with 0.1 N ceric sulfate. Perform a blank determination, and make any necessary correction. Each ml of 0.1 N ceric sulfate is equivalent to 27.80 mg of FeSO4•7H2O.

2007-01-31 17:32:25 · 3 answers · asked by hamid 1

I need to purge a tank of air and need to know if the nitrogen will sink to the bottom of any remaining air.

2007-01-31 16:59:01 · 7 answers · asked by grantm880 1

Why does it generally decrease as you go from left to right across a row on the periodic table??

2007-01-31 16:57:45 · 3 answers · asked by Tracey Lee ♥ 2

2007-01-31 16:10:02 · 3 answers · asked by MCR lover4ever 1

1- The population density of worms in a particular field is 25 worms per cubic meter of soil.How many worms would there be in the top meter of soil in a field that has dimensions of 1.00 k by 1.5 k?

2- Convert:
a. 61 F to C
b. -7F to C
c. -41C to F
d. 63C to F

3- Antarctica has an area of 5,500,000 mi^2 w/ an average height of 7500 ft.Without the ice, the height is 1500ft.Estimate the Mass of this ice (2 Significant Figures).
The Density of the Ice= 0.917 g/cm^3
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1- ?

2- I'm not sure if they are right. Also what's the "rule" with Significant Figures when it comes to Temp Conversion? Are my sig figs okay?

a.16.111
b. -21.6666
c. -41.8
d. 145.4

3- ? I though I could do the Mass formula... but that's not working out so well... = /
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UgH...Someone please help explain these to me. My book is so useless, it doesn't explain things properly & there aren't any helpful examples. I would really appreciate the help. Thank You so much! = )

2007-01-31 16:05:44 · 2 answers · asked by Miss*Curious 5

I have a big test tomorrow, and one of the samller things listed that will be on it is net ionic equations and total ionic equations.
Can anyone explain these to me? I looked them up in the textbook and I still don't understand

2007-01-31 15:34:33 · 1 answers · asked by strawberry 7 2

most ppl are the saying that this is bcoz of friction but the answer is not friction as it is related to chemistry. Plz help out!

2007-01-31 14:38:07 · 5 answers · asked by Anonymous

2007-01-31 14:37:18 · 3 answers · asked by ~ :) 1

You are given 1L of ethanol.

If you place this 1L ethanol in a 3m x 2.5m x 2.5m room, not all of the ethanol will evaporate.

The Question, then, is:
How much will remain if the vapor pressure of ethanol at 25C is 59mm Hg and the density of the liquis at 25C is .785 g/cm^3?

2007-01-31 14:32:06 · 3 answers · asked by Christie 3

2007-01-31 14:29:21 · 3 answers · asked by chocolateluver 2

Assume that 3.65 x 106 kJ are needed to heat a swimming pool. If this energy is derived from the combustion of methane (CH4) at standard conditions (25 oC and 1 atm) what volume in liters of methane must be burned?




The heat of combustion of methane is 889.967 kJ/mol. The density of methane is 0.0680 kg/

2007-01-31 14:15:42 · 2 answers · asked by Christie 1

And also, what would a Lewis dot structure look like for Copper and Iodine?

Help with either question would be GREATLY appreciated.

2007-01-31 14:11:23 · 1 answers · asked by aaaaaaaaaaaaaa555 3

Ok so I'm a senior in college trying to remember chemistry from long long ago. Specifically weak base titration. We have a solution of ammonia in water and we titrate it with 1.04 M HCl and have to figure out the number of moles of ammonia. So I use the amount of HCl used to find the moles of H+ present. The moles of H+ is equal to the moles of OH-. Then I used
Kb = [NH4+][OH-]/[NH3] to find out how much NH3 was in the water. It makes sense to me and seems to be right bt I don't remember for sure.

2007-01-31 13:50:41 · 6 answers · asked by Jake S 5

must be science related.

2007-01-31 13:26:57 · 1 answers · asked by tkotkon 2

1. 5.75 x 10^24 atoms Al

2. 3.75 x 10^24 molecules CO2

3. 3.58 x 10^23 formula units ZnCl2

4. 2.50 x 10^20 atoms Fe

2007-01-31 12:53:05 · 4 answers · asked by User84 4

What mass in grams of Na is needed to synthesize 5.05 grams of Na2S from its elements ?

2007-01-31 12:45:40 · 2 answers · asked by Latina129 2

can you break those solvents into the catergories of polar and nonpolar

2007-01-31 12:29:17 · 4 answers · asked by Anonymous

Assume that 4.08 x 106 kJ are needed to heat a swimming pool. If this energy is derived from the combustion of liquid ethanol (CH3CH2OH) at standard conditions (25 oC and 1 atm) what volume in liters of ethanol must be burned?




The heat of combustion of ethanol is 1366.818 kJ/mol. The density of ethanol is 0.789 g/cm3


Enter a numeric answer only. Do not enter units.

I tried 166465847.8 and 166.4658 but they both came up wrong

2007-01-31 12:22:24 · 3 answers · asked by Anonymous

Please give a clear understandable anwser.

2007-01-31 12:21:09 · 2 answers · asked by K Dub 1

2007-01-31 12:18:41 · 1 answers · asked by Anonymous