Chemistry - November 2007

We're supposed to find how many moles and atoms/molecules in each compound/element. I am almost completely lost... I know theres something to do with taking the mass and dividing it by the formula weight and multiplying it by 6.02 x 10^23, but i don't know if that's just for moles or if its molecules/atoms... or both? I'm about to rip my hair out Can someone PLEASE PLEASE PLEASE help? (i.e. Calcium Chloride, CaCl2 2H2O, 14.439 g of it.)

2007-11-01 06:08:10 · 3 answers · asked by NoID 2

There is 36.50 cm cubed of liquid. Which apparatus is the most accurate to measure its volume: A burette or a pipette

2007-11-01 06:02:14 · 6 answers · asked by kewl_something 1

1. If 1.710 g of a gas occupies a 500-mL flask at 30 degrees C and 750 mm Hg of pressure, what is the molecular weight of the gas? (Show work, and remember to use proper units: V in liters, T in degrees Kelvin, P in atmospheres.)

2. Can a real gas ever behave as an ideal gas? Explain.


Thank you very much in advance!

2007-11-01 05:42:48 · 2 answers · asked by Kate 1

2007-11-01 05:41:11 · 1 answers · asked by IDchecker27 2

2007-11-01 05:35:37 · 1 answers · asked by Gurlie Gurl 2

1.what happens to the outermost electron in a sodium atom when the atom is heated and made to give off a line spectrum?
2.how did observations of spectra lead to conclusions that the energy given off by excited atoms is quantized?
3.Explain how atoms can be electrically neutral even though they contain charged particles? Is dthe answer to this question because they balance or level each other out.

2007-11-01 05:31:36 · 4 answers · asked by babygrlnpnk999 1

The standard enthalpy of combustion of ethene gas, C2H4(g), is -1411.1 kJ/mol at 298 K. Given the following enthalpies of formation, calculate Hf° for C2H4(g).

2007-11-01 05:23:19 · 1 answers · asked by Anonymous

2007-11-01 05:20:41 · 1 answers · asked by chile270 1

Calculate w and E when one mole of a liquid is vaporized at its boiling point (71°C) and 1.00 atm pressure. Hvap for the liquid is 37.1 kJ mol-1 at 71°C.

2007-11-01 05:20:07 · 2 answers · asked by toocool 1

A 134 g stainless steel ball bearing (sp ht = 0.50 J g-1 °C-1) at 525°C is dropped onto a large block of ice at 0°C, what mass of liquid water will form? (H°fusion = 6.01 kJ/mol H2O(s))

2007-11-01 05:18:39 · 2 answers · asked by toocool 1

Is this eqn correct?

2007-11-01 04:59:05 · 1 answers · asked by Anonymous

2007-11-01 04:54:52 · 2 answers · asked by L.B. 2

2007-11-01 04:49:34 · 3 answers · asked by Anonymous

2007-11-01 04:30:22 · 1 answers · asked by alanis118 1

cat- for both negative and positive?

how to understand the cat- means descent in the words of cathode, cation.

the same thing happen to anode and anion.
Thanks.

2007-11-01 04:03:08 · 2 answers · asked by for2000 3

2007-11-01 03:57:10 · 3 answers · asked by b a 1

This is a general knowledge question on a parents quiz, for my kids school?

Help anyone???

2007-11-01 02:50:24 · 24 answers · asked by bakebeanie 2

2007-11-01 02:30:40 · 3 answers · asked by nicole c 1

2007-11-01 01:55:38 · 3 answers · asked by joan b 1

2007-11-01 01:13:40 · 2 answers · asked by Anonymous