Chemistry - January 2007

2007-01-15 15:02:47 · 4 answers · asked by saira n 1

2007-01-15 14:50:12 · 4 answers · asked by Kelly B 1

I have a test on Wednesday and I need to know the defintion of chemical bonding. I've tried the internet and I couldn't find a simple definition. Thanks! ♥

2007-01-15 14:50:04 · 1 answers · asked by asdfgh. 4

2007-01-15 14:37:27 · 3 answers · asked by Frankly 2

Are the HYdrogen atoms say 10 degrees apart or some other number?

2007-01-15 14:19:18 · 6 answers · asked by Sawdust 1

50.0 g of sulfur is mixed whit 100.0 g of iron and the mixture is heated. when the reaction is completed, 12.7 g of iron remains. what is the empirical formula of the compound formed?

2007-01-15 14:09:16 · 2 answers · asked by Anonymous

i would appriciate it

2007-01-15 14:01:17 · 6 answers · asked by Anonymous

If you put an 18g ice cube at 0C in 500g of water at 20C, what will the final temperature of the water be after the ice cube melts?

2007-01-15 13:50:53 · 1 answers · asked by Hiborn 1

here is the equation: NA2CO3 + CACL2.H20>CACO3 + 2NACL + 2H20. I have already weighed out one gram of CACL2.H20

2007-01-15 13:41:40 · 2 answers · asked by John S 1

I dont want the answer but rather how to find out the answer so i can do it on my own.....

2007-01-15 13:29:39 · 9 answers · asked by just_curious 1

i have no clue how to find the answer. i googled and everything.

"explain why magnesium metal, rather than copper metal, might be used to study the effect of concentration of hydrochloric acid on rates of reaction."

any help would be highly appreciated, thanks.

2007-01-15 13:26:12 · 6 answers · asked by Stacey 3

ok. Ifa photon of the exact same energy is shot at an electron, then it ceases to exist in that energy level and begins existing in another level. this occurs by tunneling. and at any time, that photon can be shot out of the atom. then the electron will cease to exist in that NRG lvl and Begin existing in its Previous lvl. BUT if you never know when the Photon of light is going to be shot out of the atom, WHY DO FLOURESCENT LIGHTS TURN ON INSTANTLY?!?

2007-01-15 13:23:52 · 3 answers · asked by Hannabelle 1

I cant remember what molar mass is

2007-01-15 13:16:26 · 2 answers · asked by Eddie G 1

plez help me to discusse my obseverion,I just did a draft,let me know if am doing it good or if am missing anything eles..u could also add on it...thanks

-Aim:To determine the pH of some household products

Eleven different household substances was given. Universal indicator was used to identify the pH of each household substance.One by one household was poured into test tubes and a small piece of universal indicator was droped into the particular household substance,and then perform it changed.As obsevered closely three substance was very acidic,four was neutral and four was basic.Mostly the lightier liquid changed to acidic such as the bleach,rubbing alcohole ect..and the heavier liquid such as milk (liquid),disinfectant.

2007-01-15 12:51:47 · 3 answers · asked by Anonymous

if u know what I'm talking about, then plz pay attention. This is 8th chemistry. so anyway.....this is about writing chemical formulas that contain polyatomic ions.grade chemistry. anyway, this is about
Example:

The chemical formula for a compound composed of calcium and a hydroxide ion is Ca(OH)2.

1. Ca +2 OH -1
2. Ca +2 OH-1
3. Ca(OH)2.

my question is:

the ion for Oxygen is -2
the ion for Hydrogen is -1.

so why doesnt (OH)-2 turn into (OH)-3?

2007-01-15 12:49:46 · 4 answers · asked by funkypolak17 3

I am stumped on this one...

The complete combustion of 1.00 mol of sucrose (table sugar), C12H22O11, yields 5.65 x 10 3(exp) kJ.
a). Write a balanced thermochemical equation for the combustion of sucrose.

Do I write it as an endothermic reaction because energy is absorbed (bonds are broken) in combustion? Or because it says combustion do I have to include O2 or H20 on the reactant side? Am I even on the right track? We weren't given any examples to work with in our notes and the textbook is of no use with an example. This question does not give you an equation to work with...or to balence or am I not seeing it?

b). Calculate the amount of energy that is released when 5.00 g of sucrose (about one teaspoon) is combusted.

I think for this one I can get my 2nd molar amount and then be able to find AH?

Thanks in advance for your input:))

2007-01-15 12:47:16 · 4 answers · asked by kickaburra 1

2007-01-15 12:43:48 · 1 answers · asked by Lisa 1

Chemistry is a big problem when you have a teacher who won't teach
PLEASE help

1. How many molecules are in one mole of: glucose; C(6)H(12)O(6)?
2. Calculate the mass of one mole of: glucose; C(6)H(12)O(6)?
3. How many atoms are in one molecule of: glucose; C(6)H(12)O(6)?

all I know is that she wants us to use the conversion
1 mole = 6.0221367x10(23) molecules

I've been struggling with this for TOO long and my friends and parents are no help
any help or answers you can give me is great thanks

2007-01-15 12:42:31 · 7 answers · asked by Anonymous

why the carbon in CO2 is bonded to only 2 atoms while the carbon in CH4 is bonded to 4 atoms?

2007-01-15 12:34:06 · 7 answers · asked by orange 2

My car has a 13.7 gallon tank. Assuming that gasoline is entirely made from octane(C8H18), how many POUNDS of CO2 would be froduced from my car each time I use a tank of gas? How many pounds of CO2 will produce from my car each year(I drive 21,500 miles each year)?
Some equalities you may find useful
- 1 lbs- 4536 kg
1 kg-2.205 lbs.
28.35g-3.785 liters
l inch-2.54 cm
density of octane-.855g/ml
my car averages 29.7 miles/gallon

use the following equation
C8H18 + 12 1/2 O2 --> 8 CO2 + 9H2O
if u can find the answer and show work, it would be greatly appreciated. Please hlp. thx It would be nice if u can show step by step using factor labeling or something. Please show work

2007-01-15 12:20:07 · 3 answers · asked by coolphill517 1

atoms gain/lose electrons and become ions. Why is this important to the formation of compounds?

2007-01-15 12:16:32 · 4 answers · asked by WaitingForAnswers 2

Will the helium affect the combustion of the propane?

2007-01-15 12:16:22 · 9 answers · asked by Anonymous

So I'm kind of lost. I must explain why the melting point of NaF is 993 degrees Celcius while the m.pt. of CsCl is 645 degrees Celcius. From what I understand NaF is smaller than CsCl. But, the dispersion forces are stronger between larger molecules. I don't understand why the melting point is higher for the smaller molecule. Could you please explain?

2007-01-15 12:08:19 · 1 answers · asked by okgo 4

Why are mixtures like oil and water difficult to keep mixed? and Why does frozen water expand and cold steel shrink? i am so totally lost [*] WHO EVER CAN ASNWER BOTH THESE QUESTIONS CORRECTLY AND FIRST GETS BEST ANSWERR!!!!![*] but mainly the second question...

2007-01-15 12:05:48 · 8 answers · asked by Anonymous

CH3CH2OH + O2 ==> CH3CHO + H2

2007-01-15 11:48:27 · 3 answers · asked by J.r. 3

2007-01-15 11:41:31 · 7 answers · asked by Anonymous

If so, where? What type of degree does it take? Is it boring? Do you get to go to Crime Scenes and do fingerprinting? What company do you work for?

2007-01-15 11:34:01 · 1 answers · asked by davidnicolewilson 2

2007-01-15 11:25:26 · 2 answers · asked by T.O. 2

is it that the solution becomes hot when;
1. pelletes of sodium hydroxide was dissolved in water?
2. dilute hydrochloric acid was mixed with dilute sodium hydroxide?
also why is it that the solution becomes cold when ammonium chloride crystals were dissolved in water?

Plsss Help!!!

2007-01-15 11:08:31 · 2 answers · asked by Romeo O 1

2007-01-15 11:06:06 · 1 answers · asked by mido1 1