Chemistry - March 2007

2007-03-23 15:35:14 · 3 answers · asked by Detroiter 1

Explain the difficulty that may rise if a flame test is used to identify a single cation in a mixture containing several cations.

2007-03-23 15:28:18 · 3 answers · asked by ZG786 1

1) Excess lead(II) nitrate (Pb(NO3)2) reacts with sodium iodide (NaI) to produce a yellow precipitate. Both solids are dissolved in water before the reaction.
-Write a balanced equation.

2) Explain how to calculate the Average Atomic Mass for a sample if you are given the percent abundance and the isotope mass.

2007-03-23 15:20:02 · 6 answers · asked by kickitup21 1

2007-03-23 14:56:41 · 1 answers · asked by mitch v 1

(note that Ksp is in terms of moles and liters) of Ag2CO3
Ksp = 8.10 x 10−12 (Neglect the basic properties of CO3−2)

2007-03-23 14:39:40 · 2 answers · asked by Gemini 2

2) A 4.00 g sample of a hydrate of nickel (iii) bromide losses 0.793 g of water when heated. Determine mass percentage of water in the hydrate and the formula of the hydrate. 3) A hydrated compound has analysis of 18.29% ca, 32.37 % Cl and 49.34 % H2O .What is its formula? 4) the masses of the hydrates listed below were measured, heated to drive off the water of hydration, and cooled. Then the masses of the residues were measured. Find the formulas of the following hydrates.a) 1.04 g Ni SO4.n H20 gave a residue of 0,61g b) 1.26 g CaSO4. n H2O gave a residue of 0.99g
4) A 2.50 g sample of hydrate of calcium sulfate losses 0.523g of water when heated. Determine the mass percent of water in the hydrate and the formula of the hydrate.
Can someone help me? thanks

2007-03-23 14:30:15 · 1 answers · asked by loc c 1

2007-03-23 14:12:25 · 2 answers · asked by mitch v 1

2007-03-23 14:08:33 · 8 answers · asked by deborah 2

Why do alkaline manganese cells have longer shelf life than zinc carbon cells?

2007-03-23 13:56:35 · 1 answers · asked by Anonymous

2007-03-23 13:42:19 · 5 answers · asked by Anonymous

Ka for HNO2 is 4.5x10-4

(a) the initial solution

(b) the point at which 80 mL of the base has been added

c) the equivalence point

(d) the point at which 105 mL of the base has been added

2007-03-23 13:35:40 · 1 answers · asked by mitch v 1

2007-03-23 12:54:41 · 8 answers · asked by Anonymous

I am going to be starting chemistry next semester how hard is it and what grade did you receive in it, your imput would be extremly helpful tyvm

2007-03-23 12:37:27 · 5 answers · asked by Anonymous

I need to make a 3-D model of neodymium and aam not sure what to do exactly, anything helps (neodymium is element # 60 on the periodic table of elemens).

2007-03-23 12:18:27 · 1 answers · asked by Anonymous

With single replacement what do these equations come out to be?
CaCl2 + Zn = ?
NaCl + Pb = ?
MgCl2 + Pb = ?
FeCl3 + Mg = ?

2007-03-23 12:15:56 · 2 answers · asked by mcsquare3245 2

Got tons of reactions to remember, anyone got ideas to make them stick in my head?

2007-03-23 11:58:48 · 5 answers · asked by Chuckwalla 3

What is the final temperature of 100G of water, initially at 20Degrees C, to which 1000 calories are added?
I need to figure out how to set up the formula.

2007-03-23 11:48:51 · 1 answers · asked by Toothie 2

its for my chem class lab reprot and im having the hardest time with it

2007-03-23 11:45:52 · 6 answers · asked by babs335123 3

Being I have never visited Chicago, I first learned on Wikipedia that Chicago dyes its river green on St. Patrick's Day. The Wikipedia article, as well as many sources, say the dye ingredients are a top secret. However, other sources know bits of information about it. (One site says it is a vegetable dye, other sources say it is a fluorescent dye ) How much is known about the properties and ingredients dye used in the river? One newspaper I saw online said over 50 cities wanted to know the formula. Even though the formula is not being released by the group doing the dying, but because the river is publicly accessible, I would presume that someone has taken samples of its water to a chemical lab for analysis.

So, is the green dye used in the Chicago river still a big secret?

2007-03-23 11:18:34 · 1 answers · asked by brandenads 2

of the same element?
a) triple bond, double bond, single bond
b) double bond, triple bond, single bond
c) single bond, double bond, triple bond
d) double bond, single bond, triple bond

2007-03-23 10:51:26 · 2 answers · asked by rnjes21 2

2007-03-23 10:45:37 · 2 answers · asked by rnjes21 2

of a carbon tetrachloride (CCl4)?
a) as a solution
b) as a suspension
c) as a solute
d) as a solvent

2007-03-23 10:44:31 · 1 answers · asked by rnjes21 2

a. NaCl is combined with NaOH
b. H20 is combined with HCl
c. KOH is combined with HCl
d. HCl is combined with H20S04

2007-03-23 10:42:22 · 2 answers · asked by Manuel J 1

a) the exact path taken by an electron cannot be determined, only its probable path
b) although electrons travel in circular orbits, the distance of these orbits from the nucleus cannot be measured
c) more sophisticated measuring devices must be invented before the motion of an electron can be described precisely
d) as the frequency of photons used to observe an electron increases, the precision in determining the electrons motion increases as well

2007-03-23 10:36:54 · 3 answers · asked by rnjes21 2

im making a vitamin C indicator. one of the ingredients is iodine, and i dont have it, what can i use 2 replace it???

2007-03-23 10:30:49 · 2 answers · asked by Anonymous

observe electrons?
a) infrared light would have a greater effect on the electrons position
b) the wavelength of infrared light is closer to the size of an electron
c) the resolution provided by infrared light would be greater
d) infrared light has a lower energy per photon

2007-03-23 10:29:43 · 1 answers · asked by rnjes21 2

2007-03-23 10:27:21 · 3 answers · asked by rory r 1

2007-03-23 10:25:00 · 7 answers · asked by rory r 1

I need to find a simplified color-coded diagram of calcium's nucleus that shows the particles in the nucleus on the internet. Does anyone know of any websites? Thanks.

2007-03-23 09:02:41 · 2 answers · asked by bouncy_tigger 1

The question is how many geometric isomers can exist of the complex [Cr(dmen)3]3+. I don't understand even how to figure out how many geometric isomers it can have in the first place. I don't want the answer solely, but how to solve it, so I can solve them in the future. Any tips would be super great!!

2007-03-23 08:56:47 · 2 answers · asked by pinkflahippo16 2