Chemistry - November 2007

The temperature of the balloon is increased to 38.0°C as it expands to a volume of 570. L, the pressure remaining constant. Calculate q, w, and E for the helium in the balloon. (The molar heat capacity for helium gas is 20.8 J/°C·mol.)

2007-11-25 04:33:28 · 2 answers · asked by Anonymous

1.weak and the vapor pressure is low
2.weak and the vapor pressure is high
3.strong and the vapor pressure is low
4.strong and the vapor pressure is high

2007-11-25 04:24:16 · 3 answers · asked by Q+A 22 3

Which molecule or compound below contains a pure covalent bond?

A) SCl6
B) PF3
C) Cl2
D) Li2CO3
E) NaCl

2007-11-25 03:17:44 · 2 answers · asked by Anonymous

reagents and conditions aswell please

2007-11-25 03:08:25 · 3 answers · asked by LiNnY 3

do you know some interesting facts about oxygen, is there any dangers associated with it, and where is it found in nature

2007-11-25 02:15:38 · 6 answers · asked by Anonymous

I have 188 problems to do and I can only do about 160... the rest throw me off a bit. Please help! Thanks.

A voltaic cell is constructed that uses the following reaction and operates at 298 K.

Zn(s) + Ni2+(aq) Zn2+(aq) + Ni(s)

(b) What is the emf of this cell when [Ni2+] = 2.26 M and [Zn2+] = 0.116 M?
Answer in Volts...
(c) What is the emf of the cell when [Ni2+] = 0.239 M and [Zn2+] = 0.829 M?
Answer in Volts....
---------------------------------------------------------------------------------
(a) A Cr3+(aq) solution is electrolyzed using a current of 8.25 A. What mass of Cr(s) is plated out after 2.20 days?
Answer in Grams...
(b) What amperage is required to plate out 0.255 mol Cr from a Cr3+ solution in a period of 8.00 hr?
Answer in A...
------------------------------------------------------------------------------------

2007-11-25 01:49:01 · 1 answers · asked by Jen 1

It is found in herbal medicines containing Galium verum, or Lady's Bedstraw

2007-11-25 00:53:05 · 7 answers · asked by Anonymous

organic chemistry, preparation of aldehyde

2007-11-24 21:14:43 · 7 answers · asked by prabir c 1

types of chemical bond in chemistry

2007-11-24 21:09:16 · 9 answers · asked by prabir c 1

please help me to analys this and please give the answer and solution.....
using this formula
q(sub)v = n C(sub)v dT


1. how much heat is released when 4.50g of methane gas is burned in a constant-pressure system? One mol of methane gas combined with 2 moles of oxygen releases 890 kJ of heat.

2. the specific heat of water is 4.18 J/g-k. If 10.0g of water is heated from 25degrees celcius to 50degrees celcius at constant pressure, how much heat is needed? What is the molar heat capacity of water.

2007-11-24 21:01:19 · 1 answers · asked by bench 1

2007-11-24 20:59:07 · 2 answers · asked by destroyer_marion 1

2007-11-24 20:56:34 · 1 answers · asked by Needy 1

formation of ions...???

2007-11-24 20:41:50 · 4 answers · asked by Anonymous

n which container will sugar diffuse first?last?
a. sugar + ice water
b. sugar + tap water
c. sugar + salt water

if so, why?

thnx!!!

2007-11-24 20:29:40 · 1 answers · asked by jc learner 1

I need to get some ether for an expeirment for making freebase cocaine

2007-11-24 20:15:11 · 1 answers · asked by Anonymous

tell me about all these things, i have a test tomorrow!

1- Covalent bonds (a)-sharing of electrons
(b)-single and multiple bonds
(c)-polar and nonpolar bonds

2- it says to be able to use tools to name a compound..
I dont get it, give me some examples..!

3- Metallic bonds and properties of metals - compare to ionic bonds

Thank you for your time :-)

2007-11-24 20:12:54 · 1 answers · asked by Anonymous

can you please explain what crystal lattice is and what does it do...and the properties of ionic compounds... I need to know because I have a test in two days! thanks!

2007-11-24 20:05:53 · 2 answers · asked by Anonymous

Explain:

1-the transfer of electrons
2-formation of ions
3-formation of ionic bonds
4-ionizing energy

thank you for your time.. I just really suck at science and I need your help...

2007-11-24 20:01:58 · 1 answers · asked by Anonymous

2007-11-24 19:57:56 · 2 answers · asked by Anonymous

What are the positive and negative heat effects?

2007-11-24 19:56:42 · 1 answers · asked by Mujto Kuchiki 2

2007-11-24 19:50:43 · 1 answers · asked by candy 3

Out of the two available fuel I have to select one based on the factors of economy. How to determine which one will be economically suitable? Please give details of experiment I should undertake.
Thanks.

2007-11-24 19:46:23 · 1 answers · asked by Anonymous

List their chemical bond present,hardness,solubility in water,action of heat,melting point

silicon dioxide,sucrose,sodium chloride,octadecane,and iron

2007-11-24 19:42:41 · 1 answers · asked by ??unknown?? 1

Using acidified silver nitrate would reveal the presence of chlorine ions. However, are there other possible ways to detect chlorine in a solution? For example, if I bubble fluorine gas into the solution, would chlorine be displaced and become chlorine gas which I can use litmus paper to detect?

2007-11-24 19:32:52 · 1 answers · asked by The Cow 2

sand,sugar,table salt,candle,and iron nail

2007-11-24 19:31:22 · 1 answers · asked by ??unknown?? 1

pls help//

2007-11-24 19:16:44 · 4 answers · asked by Anonymous

2007-11-24 18:45:43 · 1 answers · asked by nicky_deutzy 2

2007-11-24 18:41:38 · 2 answers · asked by xsushio 2

2007-11-24 18:04:17 · 2 answers · asked by Anonymous

i need chemistry help=]
Why do some reactions form solids in solution (precipitates), while others do not? Does the lack of a solid forming point to a non-reaction?

thanks

2007-11-24 16:58:46 · 2 answers · asked by confuzzled 1