Chemistry - November 2007

i have to do a project for school and i have to make up a cool fact using the mole. and to refresh your memory, the mole refers to 6.02 x 10^23 of anything (Avogadro's number).

So heres the problem...
if i wanted to take a mole amount of pictures (6.02x10^23 pictures), and it takes me 5 seconds to take a picture, how long would it take me to take a mole amount of pictures?

show work please.... :)
and if you know how to do it the dimensional analysis way, please tell me how to do it that.
thanks :)

2007-11-18 14:58:10 · 1 answers · asked by sara 3

2007-11-18 14:54:04 · 3 answers · asked by DeeDee 1

2007-11-18 14:53:49 · 1 answers · asked by dylan v 1

?

2007-11-18 14:43:07 · 2 answers · asked by ♥...........♥ 5

2007-11-18 14:41:32 · 3 answers · asked by DeeDee 1

1. Is there a safe way to create helium Because- I was wondering like helium in a container size of ur finger if u open the container it has enough helium to fill a balloon .

2. On whopee cushion the bottome part air doesnt come out but you can blow in air. is there a way to that to make it easy to put in air but very hard harder then a whopee cushion to take out the air?

3. On whopee cushion how do they make it so that air goes in but not out?

2007-11-18 14:36:51 · 1 answers · asked by Anonymous

Please help me to understand this! thanx!

2007-11-18 14:20:48 · 4 answers · asked by Anonymous

i cant remember the name of it, if you put it on a cloth and put it to someone's mouth it knocks them unconscience

2007-11-18 14:08:21 · 1 answers · asked by brian c 1

(a) Calculate the mass of Li formed by electrolysis of molten LiCl by a current of 8.2 104 A flowing for a period of 14 hr. Assume the electrolytic cell is 70. percent efficient.

answer = 210000

(b) What is the energy requirement for this electrolysis per mole of Li formed if the applied emf is +8.4 V?
answer in kWh/mol

2007-11-18 14:04:02 · 1 answers · asked by softshimmer 2

these last questions i couldnt find in my textbook... help please!!

27. Why can a p sublevel hold six electrons while the s sublevel can hold no more than two electrons?

28. What do electrons and light have in common?

29. Of a set of four quantum numbers, how many of these numbers can be shared by more than one electron of the same atom?

30. When does an electron in an atom have the lowest related?

31. How are the frequency and wavelength of light related?

32. Why does an electron occupy the 4s orbital before the 3d orbital?

33. The element sulfur has an electron configuration of 1s2 2s2 2p6 3s2 3p4

2007-11-18 13:39:05 · 2 answers · asked by rebeccapolsh333 2

1)heating 100.0 grams of copper(ii) sulfate pentahydrate and obtaining 58.2 grams of anhydrous copper(ii) sulfate. What percent yield was obtained in this experiment? CuSO4 x 5H2o + heat --> CuSO4 + 5H2O
2)Find the percent composition by mass of phosphoric acid, H3PO4
3) Find the emperical formula for a compound that has the following percentage composition by mass: 10.04% carbon; .84% hydrogen; 89.12% chlorine.


Any help would be thankful. I just do not understand how to do these specific types of problems.

2007-11-18 13:38:28 · 1 answers · asked by chipmunkriot 2

2007-11-18 13:30:35 · 2 answers · asked by hondarider400at 3

NaCl has a lattice energy of -787Kj/mole. consider a hypothetical salt XY. X^-3 has the same radius of NA^+ and Y^-3 has the same radius as Cl^-.

Estimate the lattice energy of XY?

E= ?KJ/Mol

2007-11-18 13:29:33 · 1 answers · asked by FANTASY 2

DOES ANYONE KNOW WHAT IN A HOUSE OR IN A GARAGE OR ANYWHERE YOU CAN FIND THESE ELEMENTS?? - MANGANESE, BROMINE, AND BERYLLIUM???? HeLp Me!! PLEASE!!

2007-11-18 13:17:38 · 14 answers · asked by Anonymous

why are the atomic masses listed on the periodic table decimals values , and not whole numbers ... ?

2007-11-18 13:16:26 · 1 answers · asked by Anonymous

A phosphate buffer (H2PO4-/HPO42-) has a pH of 8.3. Which of the following changes will cause the pH to increase?
dissolving a small amount of Na2HPO4
dissolving a small amount of NaH2PO4
adding a small amount of dilute hydrochloric acid
adding a small amount of dilute phosphoric acid
making the buffer more concentrated by removing some water

2007-11-18 13:16:12 · 1 answers · asked by jennifer 2

a. (CH3)3CNH2
b. CH3NH2
c. (CH3CH2)3CNH2
d. all of these

2007-11-18 13:04:31 · 2 answers · asked by tessababy992006 1

a. a basic -OH group
b. a tertiary alcohol group
c. an aliphatic ring structure
d. an -OH group attached to an aromatic ring

2007-11-18 13:03:36 · 2 answers · asked by tessababy992006 1

A cylinder with a piston is filled with ideal gas. The gas temperature is held at 350 K. The cylinder is heated by an oven through a square metal rod connected between the oven and the cylinder. The rod has sides d = 2 cm and length L = 1.8 m.

a) If the oven is held at 600 K, and the heat current conducted through the metal rod is 28 W, find the thermal conductivity (k) of the metal in the rod ( ans in W/m K )

(b) For a larger cylinder at 350 K, a heat current of 50 W is needed. If we use the same metal rod to conduct heat, find the oven temperature in Kelvin that will maintain the necessary heat current.

2007-11-18 12:56:56 · 1 answers · asked by Ter-ree-sa 2

a bottle of PbSO4 contains 158.1g of the compound. How many moles of PbSO4 are in the bottle?

could you show how please.

2007-11-18 12:23:08 · 3 answers · asked by Anonymous

A KMnO4(aq) solution is to be standardized against As2O3(s) . A 0.1078g sample of As2O3 requires 22.15 ml of the KMnO4 (aq) for its titration . what is the molarity of the KMnO4(aq)?

5 AS2O3 + 4 MnO4 + 9 H2O + 12H ----> 10 H3AsO4 + 4 Mn

2007-11-18 12:22:37 · 1 answers · asked by Anonymous

Predict whether the following reactions are spontaneous or not.
Pd^2+ + H2 → Pd + 2H^+ ..... Pd^2+ + 2e^- → Pd .....E°=0.987V
Ni^2+ +H2 → Ni + 2H^+....... Ni^2+ + 2e^- → Ni .......E°=-0.250
From your answer, decide which of the above metals could be reduced by hydrogen. Identify the oxidating agents and reducing agents in the reaction.

can someone please help me solve this question? and tell how you got it.
thank you.

2007-11-18 12:17:26 · 1 answers · asked by abc 1

I read in a textbook that it's possible to burn a banana and get the yellow flame that indicates potassium is present.
I thought it might make a good classroom presentation, but my banana doesn't burn!

2007-11-18 12:15:05 · 2 answers · asked by P D 1

what is a substance plz give site where you found it!

2007-11-18 12:14:52 · 1 answers · asked by Anonymous

My Chemistry teacher told me once. Something to do with H2O in the air when it rains.. suppose to make it warmer.. but i forgot the whole explanation.
Does anyone know?

2007-11-18 12:09:19 · 7 answers · asked by MJoneSsssssss 1

Can you show how to do it please

2007-11-18 12:08:35 · 2 answers · asked by Anonymous

Boyles, Charles, Ideal Gas Law, Avagrado's Law, Combined Gas Law

When I read an equation, I am having trouble deciding which law to use to solve the equation. Any suggestions?

2007-11-18 11:50:51 · 2 answers · asked by Emerson 5

2007-11-18 11:43:31 · 1 answers · asked by Brat 1

Assume that the readings of inexpensive thermometers for the temperature of the freezing point of water are normally distributed, and have a mean of 0 degree C and a standard deviation of 1 degree C. Find the indicated probability where z is a reading in degrees Celsius. P(-1.80 < Z < 1.80)

2007-11-18 11:40:50 · 1 answers · asked by austin 1

A 4.40 g piece of solid CO2 (dry ice) is allowed to vaporize (change to O2 (g)) in a balloon. The final volume of the balloon is 1.00 L at 300 K. What is the pressure of the gas?

1) 0.122 atm
2) 122 atm
3) none of these
4) 2.46 atm
5) 246 atm

2007-11-18 11:36:27 · 3 answers · asked by Anonymous123 1