Chemistry - November 2007

2007-11-25 11:59:30 · 1 answers · asked by Breanna R 1

how would you do this if the atomic mass of silver is 108?

thnaks

2007-11-25 11:58:59 · 1 answers · asked by snoboarder2k6 3

Octane reacts with oxygen to produce carbon dioxide and oxygen

2007-11-25 11:48:31 · 4 answers · asked by WAKA 1

XD
i have quite a few questions i want to ask and check over with like little things like states and stuff xd if anyones not that busy have a look!

1)Ca(s)+ 2H2O(L)>Ca(OH)2 (aq)+H2(g)
Nh4cl (s)+ h2o> NH4cl(aq)? have no idea on that

2)to find molar ethaply for calcium of water
i do n= mass/molar mass to get moles for ca
do q=mc T to get heat for water
then molar ethaply is q/ moles of ca
i have all the values but those are the right steps?

it will be same for NH4CL(ammonium chloride)

3) and dissoultion of ammonium chloride with water is endothermic becasue heat was absorbed since the final temperature went down

4)if more calcium was added to the calcium with water reaction.. what will happen to molar entaply? it will go down since the entaply is going to be divided by a higher number right

5) this question was asking for heat or enthaply change of both equations.. i think (heat and enthaply change is the same thing right)

to get q its just mc delta T right

6) i have no idea how to write thermal equations for both of em so help here will be nice xd

7)calcium with water is exothermic becasue heat was produced on the products side(temperature increased) ammonium chloride with water is endo cuz heat was absorted final temperature lowered
but i think this question was worth 6 marks.. i dont know how i can do a 6 mark answer

2007-11-25 11:33:23 · 2 answers · asked by Bob W 1

How many moles of C atoms are in 1 mol of Sucrose (C12H22O11)?

How many C atoms are in are in 1 mol of Sucrose?


The word "atom" and throws me off. Is there anyone that can exlain?

Thanks Guys!

2007-11-25 11:32:03 · 2 answers · asked by Anonymous

2007-11-25 11:25:07 · 2 answers · asked by Anonymous

What is the density of air??
(i need a number)

thanks!<3

2007-11-25 11:19:42 · 1 answers · asked by Anonymous

the specific heat capacity of copper is 0.385 J/g * k waht quantity of heat is required to heat 168g of copper from -12.2 degreers celcius to +25.6 degreees celcisu
thank you
the answer is 2.44 kJ
i just dont know how to do the problem

2007-11-25 11:13:09 · 1 answers · asked by Anonymous

I have to relate pictures like actual pictures of people, and stuff....someone playin soccer...etc. they can't be planned out. but the pictures have to relate to atleast one of these..
Dipole-dipole Forces
Compounds
Kinetic engergy (particle level)
Metalloids
Mixtures
Potential energy (particle level)
Adhesive forces
Cohesive forces

I have ideas for a couple....i just have to figure it out..but, do you have any ideas how any of these things could link to any sort of pictures? thank you. i'm not asking for answers, and this isn't due until december, i just want to start figuring things out....
and how would i be able to compare a body of pool water with hydrogen bonding??
and would sand be a good example of a mixture??

2007-11-25 11:03:45 · 1 answers · asked by mahbabesgrl 1

How many Liters of HI would be produced from 25.0 Liters of I2 in a reaction with a sufficient amount of H2?
first I balance-
H2 + I2 = 2 HI
then ratio is 1 H2 + 1 I2 = 2 HI, so then the ratio is 2 HI - 1 I2
25.0 times 2 divided by 1 = 50.0 liters of HI ?

2007-11-25 10:32:19 · 1 answers · asked by Boo Radley 4

a)it takes more energy to ionize the electron from n=3 than from the ground state.
b)the electron is further from the nucleus on average in the n=3 state than n=1 state.
c)the wavelength of light emitted if the electron drops from n=3 to n=2 is shorter than that from n=3 to n=1
d) the wavelength emitted when electron returns to ground state from n=3 will be the same as wavelength of light absorbed to get from n=1 to n=3
e)for n=3, the electron is in the first excited state

2007-11-25 10:30:29 · 4 answers · asked by KM 1

2007-11-25 09:52:08 · 3 answers · asked by 5445 1

If 4.83mL of an unknown gas effuses through a hole in the same time it takes 9.23mL of Ar to effuse through the same hole, under the same conditions, what is the molecular weight of the unknown gas?

ANy help appreciated. My text book isn't very helpful. It gives one formula but no explanation and I cant use the formula for this problem.

Thanks

2007-11-25 09:06:59 · 1 answers · asked by Jen 2

How would i do that problem

2007-11-25 09:00:37 · 3 answers · asked by Anonymous

1.) Ammonium Phosphate

2.) Barium Iodide

3.) Potassium Sulfate

4.) Lithium Sulfide

5.) Calcium Oxide

6.) Magnesium Carbonate


It would help if you explained to me how you did it....

2007-11-25 08:58:47 · 2 answers · asked by Anonymous

i need to get this answer quick!
So please answer!

2007-11-25 08:50:41 · 1 answers · asked by Anonymous

2007-11-25 08:49:27 · 1 answers · asked by tricia b 1

the Gas over water.

2007-11-25 08:38:00 · 1 answers · asked by Anonymous

a) A few drops of aqueous ammonia are added to aqueous copper(II) sulfate and then a large excess is added.
b) Sulfur dioxide gas (a strong reducing agent) is bubbled through acidified potassium dichromate(VI).
c) Aqueous iron(II) sulfate is warmed with excess aqueous hydrogen peroxide and then aqueous sodium hydroxide is added to the product.
d)Solid manganese(VI) oxide is added to aqueous hydrogen peroxide.

2007-11-25 07:49:36 · 2 answers · asked by Frank S 3

What is the maximum useful work which can be obtained from a hydrogen-oxygen fuel cell that produces 1.75 kg of water at 25°C?

(Assume 1 atm pressure for the gases.)

2007-11-25 07:49:28 · 1 answers · asked by Anonymous

2007-11-25 07:29:24 · 3 answers · asked by Speeding D 4

A) 25.00mL of a 4.500 M H2SO4 solution.
B) 25.00 mLof a 0.500 M H3PO4

2007-11-25 07:25:04 · 2 answers · asked by missy 1

I guess the Good Lord protects fools, because I am still alive. I had some Aluminum parts I needed to clean, and had read that muriatic acid would do the job. Placed the parts in a container in the back of my shed, THINKING it would need to soak for a day or so. WELL, the reaction was EXTREMELY violent, rapidly frothing over the container and with CLOUDS of "smoke" that drove me from the shed.
I managed to get it under control, and poured several pounds of BAKING SODA on the resulting mess.

IT has quit foaming, and SEEMS inert, BUT WHAT DO I HAVE NOW THAT I HAVE MIXED MURIATIC ACID AND BAKING SODA?????

2007-11-25 07:14:44 · 0 answers · asked by Anonymous

QUESTION: I need to write out this word equation using formulaes: (is my answer right)

1) Aluminum nitrate reacts with lithium sulphate to form aluminum sulphate and lithium nitrate.

ANSWER: Al(NO3)3 + Li2SO4 ---> Al2(SO4)3 + LiNO3

(IS THAT RIGHT?)

2007-11-25 06:46:25 · 1 answers · asked by ®åp Muziκ™ 6

Predict the bond angles about each nitrogen in the dinitramide ion.
NNN
a. 90°
b.107.5°
c.109.5°
d.120°
e.180°
ONN
a.90°
b.107.5°
c.109.5°
d.120°
e.180°
ONO
a.90°
b.107.5°
c.109.5°
d.120°
e.180°

*Thank you! & Could you also please explain how you determined the answer?

2007-11-25 06:20:59 · 3 answers · asked by Anonymous

Normal Quantum Number Values are
primary-N: 1 to infinity
secondary-L: 0 to (N-1)
magnetic-M:-L to +L
spin-S: +1/2, 0, -1/2
What if I change some of them, and my new set of quantum number values is:
primary-N: 1 to infinity
secondary-L: 0 to N
magnetic-M:-L to +L
spin-S: +1, 0, -1

Can you please tell me how this would change the electron configuration of an element, and therefore how the location would change on the periodic table of elements?

Can you please five me the old and new electron configurations for some elements of your choice so that I can understand better?


Thanks soooo much!!!

2007-11-25 06:11:23 · 3 answers · asked by Bollywood Masti 4

A(aq)+B(aq)-->AB(aq)
Info:
Specific heat=4.18J/(g*'C)
Density= 1.02g/mL
Solution A, =25.0 mL, 0.60 M, 21.4'C
Solution B, =25.0 mL, 0.60 M, 21.4'C
Solution AB, =1.0 mole, 25.3'C

2007-11-25 06:05:37 · 1 answers · asked by Anonymous

when burning gasoline what happens to the gas and why is it exothermic?

2007-11-25 05:25:09 · 4 answers · asked by sweet angel 2

The temperature of the calorimeter increases by 3.2°C. Calculate the energy of combustion of quinone per gram and per mole.

2007-11-25 05:08:18 · 1 answers · asked by Anonymous

(a) Calculate the energy required to raise the temperature of 140.0 g Ag from 273 K to 295 K.
J

(b) Calculate the energy required to raise the temperature of 1.0 mol Ag by 1.0°C (called the molar heat capacity of silver).
J/mol°C


(c) It takes 1.35 kJ of energy to heat a sample of pure silver from 12.0°C to 15.7°C. Calculate the mass of the sample of silver.
g

2007-11-25 04:48:30 · 2 answers · asked by Anonymous