Chemistry - February 2007

2007-02-26 23:32:24 · 1 answers · asked by amazing_sweet_angel 1

2007-02-26 22:55:49 · 8 answers · asked by scottz121 1

2007-02-26 21:50:08 · 2 answers · asked by mating 1

1.) According to Arrthenius , what are the characteristics of acids and bases?


2.) How do Hydronium ions form? why do they form in aqueous acid solution?

3.)what are conugate acids and bases?

4.)there are 3 common theories of acids and bases.
explain how each of the ff. theories defines acids and bases.
a.) Arrhenius
b.) Bronsted-loury
c.)Lewis

2007-02-26 21:39:11 · 2 answers · asked by FaLLen_sIrEn 1

2007-02-26 21:17:43 · 3 answers · asked by ianne 1

How do scientists detect new elements (such as element-118) if they only last milliseconds before disintegrating?

2007-02-26 21:15:53 · 2 answers · asked by sap 1

2007-02-26 20:43:30 · 1 answers · asked by blubbablub 1

I am planning to do a lab, and it says for us to:
1) make a solution of lead nitrate (power form) and a separate solution of potassium iodide (powder form).
My question is, how do you make the solutions?
do you just mix it with water?
after, would the solutions be a clear color? or what other observations would I have? I already did this lab once, but it failed, so i have to redo it, and I would like to know what to expect.

2) then we have to mix the two solutions together
after seeing another group, it turned yellow, and a precipitate formed.
is this correct?

2007-02-26 20:06:15 · 4 answers · asked by blubbablub 1

Could someone please explain?

2007-02-26 19:42:19 · 7 answers · asked by Anonymous

2007-02-26 19:08:17 · 2 answers · asked by emiro higure 1

2007-02-26 18:30:18 · 1 answers · asked by Anonymous

2007-02-26 18:18:27 · 2 answers · asked by Anonymous

2007-02-26 18:11:41 · 5 answers · asked by f20ash 2

2007-02-26 17:39:52 · 3 answers · asked by cutelagayguy 4

2007-02-26 17:19:05 · 7 answers · asked by hafiz a 1

2007-02-26 17:10:37 · 2 answers · asked by hollerblue 1

i have a few questions that i want to ask and compare...
1. The neutron is electrically neutral.....i picked true
2. Most of the mass of an atom is due to the protons and neutrons..i picked true
3. The charge of an electron is equal, but opposite, to the charge of a neutron....false
4. The proton and the electron have about the same mass....false
5. The mass number is the number of protons. ...false

2007-02-26 16:42:25 · 4 answers · asked by orange_crush_05 6

Approximate value.

2007-02-26 16:24:42 · 1 answers · asked by Anonymous

What is the molar solubility of AgCl in 1.0 M K2S2O3 if the complex ion Ag(S2O3)2^3- forms? The Ksp for AgCl is 1.8 x 10^-10 and the Kf for the complex ion is 2.9 x 10^13

2007-02-26 16:22:49 · 0 answers · asked by Anonymous

What volume of 0.100M NaOH is needed to make 100.0mL of a pH6.00 buffer if one starts with 50.0mL of 0.100M KHP? Ka2 = 3.1 x 10-6.

2007-02-26 16:21:17 · 2 answers · asked by Anonymous

What is the pH of the solution after the addition of 12.65mL of acid solution

2007-02-26 16:18:45 · 1 answers · asked by Anonymous

2007-02-26 16:16:23 · 4 answers · asked by wei jun 1

in table below. A 0.10 M solution of the unknown salt has a pH of 5.87 . What is the actual formula of the salt?

Values of Kb for some common weak bases.
Ammonia 1.8e-5
Methylamine 4.38e-4
Ethylamine 5.6e-4
Aniline 3.8e-10
Pyridine 1.7e-9
Please help me with this problem related to acids and bases
Thanx in advance.

2007-02-26 16:07:33 · 1 answers · asked by Anonymous

what is atmospheric pressure and what causes it

2007-02-26 16:04:17 · 2 answers · asked by Anonymous

thanks alot to anyone who can show me how to do it or tell me an answer....

As shown in the image above a sample of sodium bicarbonate is heated, producing oxygen gas. The volume of gas collected is 260.mL at 21.0 degrees C and 760.0 Torr of total pressure. How many moles of carbon dioxide are produced?


i dont think the image really matters in the problem, the gas is just being collected in a glass container...thanks!

2007-02-26 15:57:50 · 3 answers · asked by hmmmmmmmm 1

C2H5OH(l) + 3O2(g) 2CO2(g) + 3H2O(l), DH = -1.37 x 103 kJ
For the combustion of ethyl alcohol as described in the above equation, which of the following is true?

I. The reaction is exothermic.
II. The enthalpy change would be different if gaseous water were produced.
III. The reaction is not an oxidation-reduction one.
IV. The products of the reaction occupy a larger volume than the reactants.


A. I, II
B. I, II, III
C. I, III, IV
D. III, IV
E. Only I
I think I and II are correct, but I am not sure about the others. Please help.

2007-02-26 15:55:35 · 1 answers · asked by Anonymous

Calculate DH° for the reaction C4H4(g) + 2H2(g) C4H8(g), using the following data:
DH°combustion for C4H4(g) = -2341 kJ/mol

DH°combustion for H2(g) = -286 kJ/mol

DH°combustion for C4H8(g) = -2755 kJ/mol


A. -128 kJ
B. -158 kJ
C. 128 kJ
D. 158 kJ
E. none of these

Just by doing the math, I am getting 158 kJ. But I am unsure. Is this one of those problems where I am supposed to change the sign? Please help.

2007-02-26 15:54:21 · 1 answers · asked by Anonymous

What is the solubility (in mol/L) of PbCl2 in a 0.15 M solution of CaCl2? [Ksp (PbCl2)=1.6 x 10-5]
what am i doing wrong here?
1.6*10^-5= x(.15)^2
x=7.11*10^-4

and that should be [Ca]=x=[PbCl2] right?

2007-02-26 15:39:22 · 2 answers · asked by Justin T 1

In addition to the difference in temperature between freezing point of solvent and freezing point of solution and the molal freezing point depression constant for solvent, which of the answers below gives the minimum data required to determine the molecular mass of a nonionic substance by freezing point depression technique?

A) No further information is needed
B) Mass of Solute
C) Mass of solute and mass of solvent
D) Mass of solute and volume of solvent
E) Mass of solute, mass of solvent and vapor pressure of solvent.

Please explain to me which one is the answer

2007-02-26 15:11:55 · 3 answers · asked by Keely A 1

Blood in the human body transporting O2 and CO2

CO2(g)+H2O(l)<------>H2CO3(aq)
H2CO3(aq)+H2O(l)<------>HCO3-(aq) + H3O

Extremely rapid breathing decreases the H2CO3 concentration in the blood through increase elimination of dissolved CO2.

Am I correct when I am guessing that the H3O+ concentration in the blood will increase due to a shift to the right of this equation?

2007-02-26 15:07:47 · 2 answers · asked by calculusgirl1979 2