Chemistry - October 2007

2007-10-14 08:58:13 · 2 answers · asked by Melanie 1

When 194 mL water at 34°C is mixed with 78 mL water at 69°C, what is the final temperature? (Assume that no heat is lost to the surroundings and that the density of water is 1.00 g/mL.)

explination would be nice, answer is fine too.

2007-10-14 08:48:33 · 1 answers · asked by Anonymous

how can ice met at 0 degree celcius and water freeze at the same temperature of 0 degree celcius? at 0 degree celcius, what do you have, water or ice?

i cant figure out the answer!!

2007-10-14 08:35:11 · 2 answers · asked by karishmaaaaaaaaaaaaaaaa<33 2

2007-10-14 08:30:37 · 2 answers · asked by lisandra 1

2007-10-14 08:01:34 · 1 answers · asked by Anonymous

I've been to wikipedia, but it doesn't say anything about the manufactoring of it. I've googled it, typing in every way I can think of to get it answered, but I can't find anything except it being found naturally in some edible fruits and green and black tea. If you know where it is found in nature besides those, that would be awesome too....

2007-10-14 07:41:26 · 4 answers · asked by Desi 1

Is there an equation that shows this?

2007-10-14 07:21:25 · 2 answers · asked by de4th 4

2007-10-14 07:13:34 · 2 answers · asked by amityville3132002 1

What volume of HCN(g) can be obtained from 70.0 L CH4(g), 70.0 L NH3(g), and 70.0 L O2(g)? The volumes of all gases are measured at the same temperature and pressure.

The Chemical Formula is
2CH4(g) +2NH3(g) + 3O2---->2HCN+ 6H2O

2007-10-14 07:13:01 · 1 answers · asked by s.weiss 1

calculate the energy corresponding to the n=3 electronic state in the Bohr hydrogen atom


calculate the energy change correspondin the excitation of an alectron from the n=1 to the n=3 electronic state in the hydrogen atom


can you show me the work too so i understand it?

2007-10-14 06:21:46 · 1 answers · asked by Anonymous

Please help me, I'm looking in my chemistry book and I can't figure it out.

2007-10-14 03:56:02 · 5 answers · asked by peacexlovexash 2

curium is an element.. curium is also a power source.Curium bio-accumulates in bone tissue where its radiation destroys bone marrow and thus stops red blood cell creation.Curium has been studied greatly as a potential fuel for radioisotope thermoelectric generators. I need an essay for this please..

2007-10-14 02:30:47 · 1 answers · asked by mia 2

how would i balance this:
HNO3 + SO2 + H2O --> H2SO4 + NO

please include your steps (algebriacally) to help me understand it a bit more

thanks in advance

2007-10-14 02:08:35 · 5 answers · asked by Jenny K 1

when ammonium thiocyanate & barium hydroxide are mixed what substances can you detect from the smell?& what is the balanced equation?(NH4+ & SCN-)please help

2007-10-14 01:43:02 · 1 answers · asked by ping 1

what is the blanced equation of copper sulfate(solution) + steel wool?please help

2007-10-14 01:38:56 · 1 answers · asked by ping 1

related to surfactant..in monolayer studies..
pls help..

2007-10-14 01:00:03 · 2 answers · asked by summeR 2

achieve octet configuration??WHY???

2007-10-13 23:12:32 · 1 answers · asked by Anonymous

2007-10-13 23:08:39 · 1 answers · asked by Anonymous

and its method of reaction in other
substance in the body.. please T_T

2007-10-13 21:55:44 · 2 answers · asked by ----- 1

please answer!

2007-10-13 18:38:01 · 4 answers · asked by Gerad W 1

I need to learn how to figure out the electron configuration of an element by just looking at the periodic table, plz do help, and thanks!

2007-10-13 18:35:23 · 2 answers · asked by 2GOODFORU 1

How many valence electrons does the ion have ?

How many electrons are in bonding orbitals ?
Enter an integer as an answer

How many electrons are in anitbonding orbitals ?
Enter an integer as an answer.

What is the bond order of the ion
Enter an integer or a decimal fraction e.g. 1 3.5

2007-10-13 18:14:00 · 3 answers · asked by esteffany 2

1) 9.52g of magnesium chloride is dissolved in 250.0ml of water
i)Determine the concentration of the solution.
ii) To prepare a 1.00molL-1 solutin of magnesium chloride, so determine the mass of MgCl2 needed to prepare 500.0ml of the solution

Thanks heaps

2007-10-13 18:06:15 · 1 answers · asked by Snowydevil 1

I have a unit test coming up in two days and want to know what a nonmetal oxide with water will yield.
In my textbook it says NO2 + H2O --> HNO3 + NO.
How does this work? Explain please! please use different examples of how this is done.

2007-10-13 17:57:24 · 4 answers · asked by H4X0Rshocks 3

A 319 mL container holds 0.146 g of Ne and an unknown amount of Ar at 35°C and a total pressure of 637 mmHg. Calculate the moles of Ar present.

2007-10-13 17:55:52 · 1 answers · asked by raleighzia 1

When 0.655 L of Ar at 1.20 atm and 227°C is mixed with 0.250 L of O2 at 501 torr and 127°C in a 400 mL flask at 27°C, what is the pressure in the flask?

2007-10-13 17:55:18 · 2 answers · asked by raleighzia 1

2007-10-13 17:50:03 · 3 answers · asked by mr.p 1

2007-10-13 17:29:34 · 1 answers · asked by fragile24 1

1 g of KIO3{potassium iodate} is dissolved in water to gives a 250.00 cm^3 solution.
25.00cm^3 of potassium iodate is pippeted into a conical flask and add about 1.00cm^3 of 0.10gcm^-3 potassium iodine solution. and also add 0.1M sulphuric acid to acidified the mixture. {THUS, Iodine solution is liberatd}

KIO3 + 5KI+3H2SO4====> 3K2SO4 + 3I2 + 3H2O

then the mixture solution is titrated with 25.00cm^3 of
sodium thiosulphate solution to reach the end point.
THe 1 cm^3 of 0.1 Gcm^-3 of starch is also added to the mixture when it is near the end point



HOW CAN I FIND THE the following a,b coefficient in the

equation?
aNa2S2O3 + bI2 ===> products where a and b are the

stoichiometric coefficients

we do not have the molarity of sodium thiosulphate, how can

I find the number of mole of sodium thiosulphate?
also why starch solution should be also freshly prepared?




potassium iodide turns yellow on standing in air.
account for this phenomenon with the u

2007-10-13 17:06:21 · 3 answers · asked by smooth lens 1

a. NH2
b. N2H3
c. NH
d. N2H2
e. N2H

2007-10-13 15:47:34 · 2 answers · asked by Anonymous