Chemistry - November 2006

2006-11-13 23:30:44 · 10 answers · asked by madhu g 1

what are the factors which affect the capacity of the buffer?

when the maximum capacity of the buffer be acheived?" show calculations"?

I need the answer, please help me

2006-11-13 20:39:22 · 1 answers · asked by Cinderella 3

what are the factors which affect the capacity of the buffer?

when the maximum capacity of the buffer be acheived?" show calculations"?

I need the answer, please help me
I will do what ever u want if u helpt me,plzzzz

2006-11-13 20:18:42 · 2 answers · asked by Cinderella 3

2006-11-13 18:30:12 · 3 answers · asked by Laisa E 1

We never did anything even close to this in class, and i cant find help in the textbook, im desperate, please help me...

"Small quantities of oxygen gas are sometimes generated by heating KClO3 in the presence of MnO2 as a catalyst:



2KClO3(s) → 2KCl(s) + 3O2(g)



What volume (ml) of O2 is collected over water at 20.0 oC by the reaction of 0.261 g of KClO3 if the barometric pressure is 722.7 mm Hg
The vapor pressure of water at 20.0 oC is 17.5 mm Hg. "

Someone told me that this is the correct was to do the problem, however the answer is incorrect, can someone please help me?

2 KClO3---> KCl + 3O2

the molecular weight of KClO3 is 122.5

so you can see that 2*122.5 = 245g of KClO3 corresponds to 3 moles of O2

0.261 g corresponds to 0.261*3/122.5 = 0.064 moles of O2

to calculate the volume you use the formula pV = nRT ;
T = 293 K and 1mmHg = 133 Pa

V = 0.064*8.31 * 293/ 722.7*133 =0.0016m^3 = 1.6 liter

2006-11-13 18:29:29 · 2 answers · asked by Paul S 2

We never did anything even close to this in class, and i cant find help in the textbook, im desperate, please help me...

"Small quantities of oxygen gas are sometimes generated by heating KClO3 in the presence of MnO2 as a catalyst:



2KClO3(s) → 2KCl(s) + 3O2(g)



What volume (ml) of O2 is collected over water at 20.0 oC by the reaction of 0.261 g of KClO3 if the barometric pressure is 722.7 mm Hg
The vapor pressure of water at 20.0 oC is 17.5 mm Hg. "

2006-11-13 17:36:20 · 3 answers · asked by Paul S 2

Small quantities of oxygen gas are sometimes generated by heating KClO3 in the presence of MnO2 as a catalyst:



2KClO3(s) → 2KCl(s) + 3O2(g)



What volume (ml) of O2 is collected over water at 20.0 oC by the reaction of 0.261 g of KClO3 if the barometric pressure is 722.7 mm Hg
The vapor pressure of water at 20.0 oC is 17.5 mm Hg.

How do you do this?

2006-11-13 17:25:37 · 1 answers · asked by Paul S 2

4.27 x 10^-3 (sodium dihydrogen phosphate)

2006-11-13 16:46:55 · 5 answers · asked by Legend 4

Iron objects such as storage tanks and underground pipelines can be protected from corrosion by
connecting them through a wire to a piece of
A) Pb
B) Ag
C) Sn
D) Mg

2006-11-13 16:39:03 · 1 answers · asked by Ruphert J 1

Which element is associated with the term "galvanized"?
A) Ga
B) Zn
C) Cd
D) Hg
E) Pb

2006-11-13 15:30:26 · 6 answers · asked by Erin C 1

I'm thinking of randomly picking the winner from the correct answers this time, rather than taking the first correct answer:

What compound with silver in it is used to develop film?

2006-11-13 15:19:12 · 7 answers · asked by Steady As She Goes 2

In an electrolytic cell, electrical energy is converted into chemical energy.
A) True
B) False

2006-11-13 15:18:02 · 4 answers · asked by Erin C 1

For a certain gas that contains only carbon and hydrogen the mass percentage of carbon is known to be 85.62
It is also known that 2.58 g of the gas has a volume of 1.00 L and a pressure of 0.980 atm at 51.0 oC.
What is the molecular formula for the gas ?

2006-11-13 15:05:29 · 1 answers · asked by Anonymous

An electrochemical reaction will be spontaneous if _____.
A) ΔG is positive
B) the standard emf of the cell is negative.
C) the standard emf of the cell is positive.
D) resistance is positive.

2006-11-13 15:04:41 · 2 answers · asked by axcryingxshame 1

Tarnished silver is coated with _____.
A) Ag2O
B) ZnS
C) AgCl
D) Ag2S

2006-11-13 14:40:16 · 6 answers · asked by axcryingxshame 1

The species that is not an oxidizing agent is _____.
A) HNO3
B) BrO3
–
C) Cl–
D) MnO4
–

2006-11-13 14:28:00 · 3 answers · asked by hmmm 2

In a mixture of H2 and CH4 gases, the partial pressure of H2 is 0.130 atm. The total pressure is 0.380 atm. The temperature is 26.0oC. If the total volume of the gas mixture is 526 mL, what is the mass of CH4 in grams?

2006-11-13 14:17:46 · 1 answers · asked by kevdubya23 1

oxidizing agents, reducing agents, acids, bases

2006-11-13 14:14:51 · 2 answers · asked by Anonymous

If I put wet clothes outside in a winter day...they freeze, but eventually they dry. Why?

2006-11-13 14:12:59 · 2 answers · asked by ABC 4

FeCr2O4 + KCO3 + O2 --> Fe2O3 + CO2 +KCrO4

I can't balence this one. All i need is it balenced, no explination, no other questions.

2006-11-13 14:02:09 · 3 answers · asked by Matt 2

sodium hydroxide, the solution would taste....
sour, bitter, salty, or sweet

2006-11-13 13:49:56 · 3 answers · asked by Anonymous

1. How can density be used to identify substances?
2.What are the relitive densities of solids, liquid, and gasses?

2006-11-13 13:40:22 · 4 answers · asked by Anonymous

2006-11-13 13:32:15 · 3 answers · asked by goodbye say bye 1

2006-11-13 13:09:22 · 7 answers · asked by Larson D 1

Propane, C3H8(g) is used as a fuel in gas barbecues. It burns in oxygen to produce carbon dioxide and water vapour.
C3H8(g) + O2(g) à CO2 (g) + H2O (g)

a) Balance the equation for this reaction
b) How many moles of propane are needed to produce 6 mol of carbon dioxide?

2006-11-13 12:58:53 · 6 answers · asked by untilyoucamealong04 3

2006-11-13 12:56:13 · 2 answers · asked by Anonymous

The atomic # is the number of protons and usually, the electrons are the same as the protons. Does this apply with isotopes where the neutrons are the only ones that change?

2006-11-13 12:51:37 · 2 answers · asked by Psycho Dork 2

2006-11-13 12:42:05 · 6 answers · asked by Doris E 1

Is Potassium Bromide soluble in water

2006-11-13 12:38:04 · 5 answers · asked by Anonymous

1) CaSO4
2) HCl
3) KNO3
or
4) Mg(OH)2

2006-11-13 12:36:31 · 3 answers · asked by frickenawesomekoreanandyouknowit 2