Chemistry - November 2007

A 4.0 liter sample of oxygen has a pressure of 95 kPa. At a temp of 198 degrees celcius the same amount of has occupies 6.0 liters and has a pressure of 101 kPa. What was the original temp of the gas?

PLEASE HELP AND ALSO SHOW STEPS OF HOW TO SOLVE THIS.... thank you.

2007-11-01 09:42:13 · 1 answers · asked by Mets Fan 1

Can anyone give me a picture of the electron configuration of silicon? I'll choice the best answer and you'll get 10 points!

2007-11-01 09:33:59 · 3 answers · asked by ♥Over-Dramatic♥ 2

from the addition of 0.040 moles of HNO3 to a buffer made by combining 0.500 L of 0.260 M HC3H5O2 ( use Ka = 1.30 x 10 -5 ) and 0.500 L of 0.520 M

2007-11-01 09:09:08 · 1 answers · asked by Anonymous

2007-11-01 09:00:48 · 6 answers · asked by Mary 1

The volume occupied by 5g NEON is ______ than the volume occupied by 2g HYDROGEN.

By the way, I want someone who actually knows this, not someone who just assumes that as 5g is a bigger amount it must be that one, k?

2007-11-01 08:43:58 · 5 answers · asked by Anonymous

If I have AgNO3 + Na2CO3 and I am asked to give the NET IONIC EQUATION - what is different than if I would just give a regular equation? Do I simply switch NO3- and CO3(2-) from one element (Ag to Na) to another? Will this be the same when mixing Pb(NO3)2 and NaCl. And mixing Sb(OH)3 and Na2S. Also - what does it mean when they say you will have a double displacement reaction?? thank you!

2007-11-01 08:39:21 · 2 answers · asked by confusedchemist 1

For instance Clorox is clorine. Baking soda is Sodium Bicarbonate ect.
I sometimes wish to acquire the chemicals quickly, but dont know what brand of product or name to purchase. The product manufacture does not always state what is in the product, as they are required for food products.

2007-11-01 08:28:33 · 3 answers · asked by mixmaster2 3

2007-11-01 08:16:20 · 2 answers · asked by nikki 3

2007-11-01 07:58:45 · 3 answers · asked by V.S. 2

chem enthalpy change?
Sadly, I have no idea how to do this problem. I have one more like it and an explanation in "idiots" terms would be great, but just an answer would be fine too...

PCl3(g) + 1/2O2(g) -----> Cl3PO(g) (delta)Hrxn= -286kJ

P4(s) + 6 Cl2(g) -----> 4PCl3(g) (delta)Hrxn=-1226kJ

(delta)Hf [P4O10(s)] = -2967kJ/mol

(delta)Hf[PCl5(g)]= -84kJ/mol

_________________________... Calculate the enthalpy change for the reaction: P4O10(s) + 6 PCl5(g) -----> 10 Cl3PO(g)


The numbers after the letters (eg, H2O2) are the subscripts...the numbers before (2 H...) are the regular numbers. Any help would be appreciated...

2007-11-01 07:55:09 · 2 answers · asked by Erika H 5

2007-11-01 07:47:34 · 20 answers · asked by Anonymous

Okay, these questions are on something I have to turn in tommorow, so I'm pretty desperate for answers. If you help me answer these and explain the process (as thoroughly and on my level (11th grade) as possible) I'll choose your answer as the best.

After calculating the percent composition of silicon dioxide, answer these questions:

1. What mass of silicon dioxide would contain 25g oxygen?

2. How many moles of silicon dioxide would contain 25g oxygen?

3. How many molecules of silicon dioxide would contain 25 g of oxygen?


I'm concerned about getting the answers, but EVEN MORE concerned about understanding HOW to get the answers!

Thanks!

2007-11-01 07:46:58 · 4 answers · asked by Anonymous

2007-11-01 07:44:40 · 2 answers · asked by Anonymous

2007-11-01 07:40:01 · 1 answers · asked by Julie W 1

Calculate the solubility in moles per liter of Hg2Cl2,
Ksp = 1.10 x 10-18 ,
Hg2Cl2(aq) ---> Hg22+ + 2Cl-

2007-11-01 07:34:57 · 3 answers · asked by mimi 1

Calculate the pH of the solution that results from the addition of 0.040 moles of HNO3 to a buffer made by combining
0.500 L of 0.080 M NH4Cl ( use Ka = 5.60 x 10 -10 )
and 0.500 L of 0.160 M

2007-11-01 07:33:51 · 4 answers · asked by mimi 1

references if possible...

2007-11-01 07:24:56 · 1 answers · asked by Anonymous

silver nitrate? is it covalent or ionic????

2007-11-01 07:24:22 · 2 answers · asked by jennifer s 1

1. How is the number of electrons in a neutral atom related to the atomic number of the element?
2. What information does the mass number of an isotope provide?
Is the answer to number 2 ... They show the average mass of an atom in a sample.

THANK YOU!!!!!!!!!!!!!!!

2007-11-01 07:23:45 · 1 answers · asked by babygrlnpnk999 1

If I have 5.0 X 10^21 atoms - how can I convert this to molecules and then to moles?

2007-11-01 07:22:41 · 4 answers · asked by confusedchemist 1

Calculate the following using the volume equation.

Find the volume of a box with length of 35 cm, width 15 cm, and height 2 cm

Calculate the following using the area equation.

What is the area of a fence that measures 60 m X 60 m?


Calculate the following using the volume equation.

Find the volume of a box with length of 10 cm, width 5 cm, and height 3 cm


Calculate the following using the area equation:

Calculate the area of a yard that measures 75 m X 40 m


Calculate the following using the volume equation.

Find the volume of a box with length of 20 cm, width 10 cm, and height 8 cm

2007-11-01 07:15:44 · 2 answers · asked by V.S. 2

such as sodium and water; 2Na+2H2o ->2NAOH +H2

2007-11-01 07:09:21 · 3 answers · asked by Anonymous

2007-11-01 07:06:33 · 2 answers · asked by amanda_setters 1

2007-11-01 07:06:02 · 1 answers · asked by amanda_setters 1

In addition to continuous radiation, fluorescent lamps emit sharp lines in the visible region from a mercury discharge within the tube. Much of this light has a wavelength of 436 nm. What is the energy (in J) of one photon of this light?

2007-11-01 06:58:23 · 1 answers · asked by jnester0289 1

2007-11-01 06:54:42 · 1 answers · asked by jnester0289 1

in the fraction of glucose (C6H12O6) with oxygen (O2) to produce carbon dioxide (CO2) and (H2O), you need a ratio of molecules equal to: 1 glucose, 6 oxygen: 6 carbon dioxide: 6 water

-how many moles of oxygen would you need?
-how many moles of carbon dioxide and water would you produce
-how many grams of carbon dioxide and water would you produce?

please explain calculations. Sorry if this is too much to ask.

2007-11-01 06:48:33 · 1 answers · asked by the common cold 4

please help me. i don't understand this at all.

a sample of nickle has 2.5 times the mass of a sample of calcium with 203 x 10^23 molecules. what is the mass of the nickle?

atomic mass of nickle: 58.6934
calcium: 40.078

avagadro's number: 6.022 x 10^23

2007-11-01 06:41:35 · 4 answers · asked by the common cold 4

1) Why is water a versitle solvent?
2) What maerials will not disolve in water
3) Why does water have a specific heat
4) Why does water have a relativly high heat of vaporization?
5) What is the biological importance of water's high heat of vaporization?
6) At equilibrium in pure water 25 degrees celcius:
a)how does the (H+) compare to the (OH)?
b)what s the (H+)

2007-11-01 06:20:39 · 4 answers · asked by Anonymous

a. How many atoms are present if the substance is lead metal, Pb?

b. How many molecules are present if the substance is sucrose, C12H22O11?

c. How many formula units are present if the substance is calcium carbonate, CaCO3?



This is a question I have to turn in tommorow at school. I've looked in my book, but it doesn't explain how I answer this question. Please help! I'll choose the best answer quickly, I promise!

2007-11-01 06:16:41 · 2 answers · asked by Anonymous