Chemistry - October 2007

Need HW help for chemistry, can anyone help me? i will award best answers promptly in return.

1.) How many molecules are in 83.8 g of Cl2?
Answer in units of molec.

2.) How many moles of atoms are there in 7:918 to the(*23*)power times
1023 atoms Mg? Answer in units of mol.

3.)For 674 g of butadiene (C4H6) calculate the
number of moles. Answer in units of mol. Calculate the number of molecules. Answer
in units of molec.

Thanks a bunch, if you can actually explain it, i'd appreciate that too.

2007-10-04 13:41:48 · 1 answers · asked by Jordan F 1

I'm soooooo stuck! THANKS.

2007-10-04 13:40:03 · 4 answers · asked by smiler! 1

Diethyl ether is a common laboratory solvent. It has limited solubility in water, thus it is commonly used for liquid-liquid extraction. Being less dense than water, the ether layer is usually on top Im Not sure but its is counterpart Dichloromethane (DCM) or methylene chloride is the chemical compound with the formula CH2Cl2. It is widely used as a solvent??????

2007-10-04 13:37:59 · 6 answers · asked by Anonymous

The visible region of the electromagnetric spectrum lies between the wavelengths:

____________ and ____________ meters
or ______________ and __________ cm
or ______________ and ____________ nanometers
or _______________and ______________ Angstoms

if you know any of this please help!

2007-10-04 13:32:48 · 1 answers · asked by Maddi J 2

2007-10-04 13:22:25 · 1 answers · asked by abi 1

how do i calculate the empirical formula of the compound formed? thank you ^_^

2007-10-04 13:21:28 · 1 answers · asked by dalastmyth 2

Does a strong reducing agent have a high oxidation potential?

2007-10-04 12:57:38 · 1 answers · asked by Anonymous

could some one explain mass number and what they look like for different isotopes

2007-10-04 12:43:39 · 4 answers · asked by Anonymous

2007-10-04 12:32:31 · 1 answers · asked by PANFILIA M 1

i do not undestand this problem at all my mom & dad have tried it but they dont understand it. please help && i'll love you forever lol


http://tinypic.com/view.php?pic=15gyxsk&s=2

2007-10-04 12:25:41 · 2 answers · asked by Nettie S 1

How many grams of phosphorus react with 39.4 L of O2 at STP to form tetraphosphorus decaoxide?
P4(s) + 5 O2(g) P4O10(s)

2007-10-04 12:20:50 · 1 answers · asked by cj 2

I am just missing something..I dont understand how to get these...I dont want the answer, I want to know how to set it up and why.


Mouthwash is 21.6% alcohol by volume. Each pint contains .358 of a pint of alcohol. density of alcohol is .876g/ml. how many kilograms of alcohol are in one bottle?

2007-10-04 12:20:29 · 1 answers · asked by mikala m 2

Today in Chemistry we were doing a lab. We used Barium nitrate, Barium chloride, Lithium chloride, Copper (II) chloride, Strontium nitrate, Strontium chloride, Calcium nitrate and Potassium nitrate. As I was crushing up one of those (I can't remember which one, but I know it was clearish/whitish), a few grains shot up into my mouth. I immediately rinsed my mouth out and then told the teacher, but he didn't take me very seriously since I couldn't remember which salt I was working with. He made me feel almost like I'd done something wrong for not paying attention to detail. Well excuse me, it could have happened to anyone.

But anyways, my question is, am I okay? Do you think this is anything to worry about? Enough to harm me and/or kill me?..

2007-10-04 12:16:09 · 12 answers · asked by isabelle.the.insomniac 2

2007-10-04 12:15:45 · 4 answers · asked by jasonz619 1

Does paper age physically when it is laminated? Does it brown or get brittle?

I don't really need to know the answers, I'm just curious.

2007-10-04 12:15:43 · 1 answers · asked by Anonymous

Which of the following is the major organic product obtained from the reaction shown in the link?
http://i20.tinypic.com/fyq3kg.jpg...

I think it is b) but what is the two on top of the structure for? Someone else says it is d) but what happens to the CH3 then?

2007-10-04 12:04:31 · 2 answers · asked by Anonymous

For a complete combustion, it takes 5 moles of pure O2 oxygen gas to react with every 2 moles of ethyne (C2H2). However, if air contains only 21% oxygen by volume, then what is the ratio of air to ethyne needed for a complete combustion? Would it be 2 moles of ethyne for 25 moles of air (since around 1/5 of air is oxygen, and 5 moles of oxygen is needed)?

2007-10-04 12:00:43 · 1 answers · asked by Anonymous

2007-10-04 11:57:59 · 3 answers · asked by Anonymous

the compounds are:
A) Ca(OH)2 B) ZnS C) Pbl2 D) Ca3(PO4)2 E) MgCO3

one more question:
Which of the following compounds would be more soluble in 1 M NH3 than in pure water? and why?

A) BaSO4 B) AgBr C) Pbl2 D) BaF2 E) Ca(OH)2

2007-10-04 11:54:13 · 1 answers · asked by MO BE 1

In the reaction of cobalt(II) chloride and hydrogen fluoride, cobalt(II) fluoride and hydrochloric acid are formed. If 18.6 moles of cobalt(II) fluoride are to be formed what is the mass of CoCl2 needed (grams)? Give an answer accurate to the tenths.

2007-10-04 11:37:02 · 1 answers · asked by Anonymous

Please help if you can... 10 points to the first right answers

2007-10-04 11:28:15 · 11 answers · asked by MsHunny 3

Air is about 78.0% nitrogen molecules and 21.0% oxygen molecules. Several other gases make up the remaining 1% of air molecules.

1) What is the partial pressure of nitrogen in air at atmospheric pressure (1 atm)? Assume ideal behavior

2) What is the partial pressure of oxygen in air at atmospheric pressure (1 atm)? Assume ideal behavior.
Express your answer numerically, in atmospheres.

2007-10-04 11:17:21 · 2 answers · asked by Anonymous

If 1.00 mol of argon is placed in a 0.500-L container at 23.0 degrees C, what is the difference between the ideal pressure (as predicted by the ideal gas law) and the real pressure (as predicted by the van der Waals equation)?

For argon, a = 1.345 (L^2 X atm)/mol^2 and b = 0.03219 L/mol

2007-10-04 11:14:32 · 1 answers · asked by Anonymous

O
/ /
R--C
\
O--H




A. Carbonyl
B. Dehydroxyl
C. acetyl
D. Methyl
E. Carboxyl

2007-10-04 11:13:43 · 1 answers · asked by jessica 1

How many grams of carbon dioxide can form when a mixture of 5.00g ethylene (C2H4) and 3.30g of oxygen is ignited, assuming complete combustion to form carbon dioxide and water?

2007-10-04 11:05:13 · 3 answers · asked by babiiashley 1

Can someone explain why the reaction of hydrochloric acid with sodium hydroxide is so violently exothermic? I mixed the two together today and the beaker in which the reaction occurred became very hot.

2007-10-04 10:41:43 · 3 answers · asked by AxiomOfChoice 2

How do you solve this problem?

Calculate the energy change in kJ for the formation of 1.23 mol of LiF(s) given the following information:
Li(g) → Li(s) : −159.4 KJ/mol
F2(g) → 2F(g) : 157.98 KJ/mol
Li(g) → Li+(g) + e− : 520 KJ/mol
F(g) + e− → F−(g) : −328 KJ/mol
Lattice energy for LiF = −1037 KJ/mol

2007-10-04 10:41:38 · 1 answers · asked by izzie 4

Reactivitiy maybe? I am not sure..

2007-10-04 09:51:29 · 5 answers · asked by Anonymous

Polonium and Beryllium .....like the chemical equation.....websites with information and how they react together what new substances do they make....

2007-10-04 09:39:40 · 2 answers · asked by *♥*Lucky Charm*♥* 2

H2(g) + I2(g) ↔ 2HI Temperature = 731K


1.50 mol of H2 and 1.50 mol of I2 are placed in a 1.00 L vessel. What is the equilibrium concentration of HI in the gaseous mixture?
The equilibrium constant is K = 49.0

2007-10-04 09:20:26 · 1 answers · asked by Peter G 3