Chemistry final exam questions on equilibrium, pH, and redox reactions

[Dooh]

Hey guys i need some help. Most of these questions i already know the answer to but i just want to make sure I'm right. My final grade is riding on this

1) If given a chemical equilibrium reaction with the delta H, by comparing the rate of the final reaction, is it possible to find the rate of reverse reaction? I don't think its possible.

2) If a reaction has a negative delta H, that means it's an endothermic reaction. Since increasing the temperature of an equation favors endothermic reaction, does that mean will shift towards the reactant?

3) How do you find the pH of a solution with given molarity of OH? Do you first solve for the pOH, then subtract it from 14 and obtain pH?

4) What is the difference between pH and pOH? Other than 1 is used for acid and other base. If a neutral solution has a pH of 7, what's it's pOH, 7?

5) In the symbol for ammonia, NH, why is the Nitrogen written first?

6) In the reaction, 2HOH + 2Na --> H_2 + 2Na+ + OH-, is the Na being reduced or oxidized?

7) What is the subatomic article with mass 1/1837 amu and -1 charge? What is this i totally don't get it.

Any help would be appreaciated. I'll check back later while i go study mroe.

 

[whozum]

a lot of these can juts be looked up in your book. The first one is possible. You should probably eelaborate on your answers to the questions if you have any.

 

[Dooh]

The problem is, i no longer have the book with me. What do you mean by elaborating it?

 

[siddharth]

It would be easier for people to help if you post what you think the correct answers are and why. That way, if you make a mistake, it will be easy to show exactly where you went wrong and how to correct it.

 

[briton]

pH + pOH = 14

 

[Dooh]

1) If given a chemical equilibrium reaction with the delta H, by comparing the rate of the final reaction, is it possible to find the rate of reverse reaction? I don't think its possible.

Well in this one, i have no idea how i would find the rate of final reaction. So if anyone can show me how to do it, i'd appreaciate it. The reaction is:

C_3H_8 + 5O_2 --> 4H_2O + 3C)_2 ::: delta H = -270 kcal/mole C_3H_8

 

[siddharth]

What do you mean by the rate of the final reaction?

At equilibirium the rate of the forward reaction is equal to the rate of the reverse reaction. So if the rate of the forward reaction is given, then the rate of the reverse reaction is also known.

 

[GCT]

1) If given a chemical equilibrium reaction with the delta H, by comparing the rate of the final reaction, is it possible to find the rate of reverse reaction? I don't think its possible.

is this the exact form of the problem? The least you can do is to post the appropriate problem.

 

[PRodQuanta]

What's the only subatomic particle that has a negative charge? If a neutron is 1 amu, a proton is 1 amu, then what particle is 1/1837 amu? Deductive reasoning.

Paden Roder

 

[wisredz]

pH is the minus logarithims of H+ ions in a solution. And this the same for pOH. Experimentations have shown that pH+pOH=14.