Chemistry - April 2007

is Na2SO4 a multiple electrolyte?

2007-04-30 16:54:50 · 1 answers · asked by Anonymous

When .100 moles of gaseous N2 and .100 moles of gaseous H2 are put into a .500 L container at 250°C, the following reaction occurs and reaches equilibrium.
N2 (g) + 3 H2 (g) <--> 2 NH3 (g)
The total pressure in the flask at equilibrium is 1.52 atm. Calculate K and KP (K Presssure) for this reaction.

2007-04-30 16:52:22 · 1 answers · asked by Anonymous

If 0.780g of phenol is dissolved in enough water to make 500ml of solution, what is the resultant pH?
C6H5OH (aq) <--> C6H50 (aq) + H............Ka=1.3x10^-10

So here the solution..i understand the first half.

0.780g x 1mol/94.11g = 8.29 x 10^-3
8.29x10^-3 / 0.500L = 0.0166M

He goes on to write this equation..

(x^2) / (0.0166 - x) = 1.3 x 10^-10

I understand that the x^2 is b/c of C6H50 & H

Why is C6H5OH...(0.0166 - x) and not (0.0166 + x)?
is it b/c the product of the reaction always takes up something?

There's a diff reaction where: N2 + O2 <--> 2NO
ea. gas is 0.300 atm.

Since the 2NO is a product...it's 0.300 - 2x? Would it still be that if the equation was reversed to 2NO <--> N2 + O2 or would it instead be 0.300 + 2x since it is on the left side?

2007-04-30 16:48:32 · 2 answers · asked by Julio 4

Does it have something to do with polarity?

2007-04-30 16:46:01 · 1 answers · asked by some guy 1

Im being asked this, for a the combustion of naphthalene using benzoic acid as a standard. I have the enthalpy of combustion of naphtalene, etc. This is for a Physical Chemistry Lab. Thanks

2007-04-30 16:44:05 · 1 answers · asked by zsway33 1

A Hydrogen gas is liberated.
B There is a transfer of electrons.
C A precipitate is formed.
D Energy is released.

2007-04-30 16:30:44 · 11 answers · asked by Blade L 1

The volume of a sample of methane (CH4) collected over water at 25.0C was 6 Liters. The total pressure was 752 torr. How many moles of hydrogen were collected?

2007-04-30 16:28:32 · 1 answers · asked by pirateprincess 2

What is the relationship between the atomic radius of the anions and cations, and the length of one side of the unit cell, for any zinc blende unit cell? Thank you!

2007-04-30 16:26:08 · 1 answers · asked by maverick7137 1

You will need an inorganic reactant. These syntheses involve carbonyl reactions.

2007-04-30 16:18:31 · 1 answers · asked by Anonymous

2007-04-30 16:16:59 · 2 answers · asked by nghuien1982 1

2007-04-30 16:16:29 · 1 answers · asked by Anonymous

2007-04-30 16:15:53 · 2 answers · asked by Anonymous

2007-04-30 16:13:35 · 1 answers · asked by Anonymous

2007-04-30 16:12:41 · 3 answers · asked by Anonymous

Hydrogen Peroxide is used as a bleaching agent, a disinfectant and medicinally as a tropical antibacterial agent. Hydrogen Peroxide decomposes according tp the reaction shown....
2H2O2(l)-->2H2O(l) +O2(g) (l= liquid g= gas)

Given the standard free energy of formation values shown below, calculate the free energy change for this reaction.
delta Gf (H2O2) = -120.4 kJ/mol
delta Gf (H2O) = -237.1 kJ/mol

Is the decomposition of hydrogen peroxide spontaneous at 25degrees C? briefly explain

2007-04-30 16:10:29 · 1 answers · asked by Tracey Lee ♥ 2

CH2=CCl2 (Vinylidene chloride) with peroxide?

Help please I have no idea.

Answer much appreciated.

2007-04-30 16:02:57 · 1 answers · asked by some guy 1

2007-04-30 16:00:48 · 1 answers · asked by woj87marta 1

I have a chemistry project due in four weeks on May 29th. I've searched around and hit a dead end. I need to find the atomic weight of lead using an electrochemical process. I need an experiment and as much background information the subject as possible. But an experiment takes priority because I need to do that at school on my own time.

2007-04-30 15:57:22 · 2 answers · asked by Crash 1

and whats LOCOM?

2007-04-30 15:56:30 · 2 answers · asked by Anonymous

Would it be possible to obtain a single pKa value for Tryptophan HCl?

2007-04-30 15:50:44 · 2 answers · asked by Anonymous

"The half-life a carbon 14 is 5600 yrs. How old is a fossil that contains 25% of the normal proportion of carbon 12 to carbon 14" please explain how you solve for this

2007-04-30 15:49:24 · 2 answers · asked by jbljackie 2

Hydrogen gas was produced by reacting magnesium metal with hydrochloric acid, 45.0 milileters of gas was produced from the reaction of .0250 grams of magnesium. The gas was collected at a temperature of 25 degrees celsius and the room pressure was 750 mm Hg (Vapor pressure of water @ 25 degree celsius= 21.3 mm Hg)


What is the pressure of hydrogen?

What was the volume of hyrdogen gas?
How many moles of magnesium were used to produce the hydrogen gas?

What is the volume of the hydrogen gas per one mole of magnesium at STP?

Thanks

2007-04-30 15:48:49 · 1 answers · asked by blinkingtrees 2

The rontgen or roentgen (R) is a unit of measurement of ionizing radiation in air, either X or gamma rays. It is named after the German physicist Wilhelm Rontgen. A roentgen is the amount of radiation required to liberate a pair of positive and negative charges from atoms of one electrostatic unit of charge in 1.00 cm3 of air at standard temperature and pressure. This corresponds to the generation of approximately 2.08 × 109 ion pairs. A dose of 500 R in five hours is lethal for humans.



If X radiation ionizes 20.4 × 1013 atoms per cemtimeter cubed, what is the ionizing intensity of the radiation measured in roentgens ?

2007-04-30 15:47:15 · 1 answers · asked by woj87marta 1

Calculate the binding energy per nucleon for the following isotopes: 11B 57Co 64Zn 78Se

i just need to see the formula for this because everything im doing is wrong. help....

2007-04-30 15:45:12 · 1 answers · asked by izzie 4

a. Does PbF2 precipitate from this solution? Ksp PbF2 = 3.7 * 10^-8 and Ka HF = 7.2 * 10 ^-4
b. What is the minimum pH at which PbF2 precipitates?

2007-04-30 15:44:27 · 1 answers · asked by ChemStudent 1

If 100 ml of a gas at -73 degree Celsius are heated at 27 degree celsius, what is the new volume
47 ml 85 ml 150 ml 167 ml

A cylinder equipped with a movable piston contains 50.0 ml of a gas. What is the new volume when the pressure is doubled at constant pressure

What is the gram equivalent weight of 1 mole of (NH4)2 NO3? (closest answer)
98.03, 78.43, 137.41, 3040.17

Two water solutions have a density of 1.00 g/mL are mixed and a reaction occurs. The temperature riss from 25 degree celsis to 27 degree celsius. Given that the heat capacity is 4.18J and that the total of mass of the water is 75.0g, what is the heat change for the reaction
6.27J 314J 125J 627J

2NO(g) + H2 (g) ---> (g) + H20(g) + 351 kJ
If the total pressure on the system is increased when the reaction represented above is at equilibrium, which of the following occurs
the concentration of H20 increse
the concentration of N2O decrese
the rate of the reaction decrese
the temperature of the system decrese
H2 gas cond

2007-04-30 15:43:47 · 2 answers · asked by Anonymous

2007-04-30 15:42:50 · 5 answers · asked by Anonymous

2007-04-30 15:34:45 · 4 answers · asked by (^_^) CHiccaaqui(^_^) 4

If 0.780g of phenol is dissolved in enough water to make 500ml of solution, what is the resultant pH?
C6H5OH (aq) <--> C6H50 (aq) + H............Ka=1.3x10^-10

So here the solution..i understand the first half.

0.780g x 1mol/94.11g = 8.29 x 10^-3
8.29x10^-3 / 0.500L = 0.0166M

He goes on to write this equation..

(x^2) / (0.0166 - x) = 1.3 x 10^-10

I understand that the x^2 is b/c of C6H50 & H

Why is C6H5OH...(0.0166 - x) and not (0.0166 + x)?
is it b/c the product of the reaction always takes up something?

There's a diff reaction where: N2 + O2 <--> 2NO
ea. gas is 0.300 atm.

Since the 2NO is a product...it's 0.300 - 2x? Would it still be that if the equation was reversed to 2NO <--> N2 + O2 or would it instead be 0.300 + 2x since it is on the left side?

My question is basically...is the addition/subtraction of X based on which side the product is on or just on the product itself?

2007-04-30 15:34:18 · 1 answers · asked by Julio 4

I asked this question a while ago, but I got conflicting answers.

Ester = O=C bond and C-O bond
acid = O=C bond and C-OH bond

which one would be more polar? and WHY?


Also, please rank the below groups in terms of their polarity. I already ranked the sub groups, but I don't know how to merge the whole list into one.

(least polar)

alkane
alkene
alkyne

Amine
Amide

Ketone
Aldehyde
Ester (?)
Carboxylic acid (?)

Alcohol (where does this go?)
Ether (where does this go?)

(Most Polar)

2007-04-30 15:27:12 · 1 answers · asked by Dave H 2