chem question

[ippie]

1. another name of "electrolytic cell " is "elecrochemical cell"???
are these two exactly the same?

2. In the molecule, H3C6H5O7, it gives three protons in the solution. How can we know this molecule gives three proton without drawing molecular structure?

3. "A 3d orbital can hold a maximum of 10 electorns."
Is this statement true? I think it's ture, but answer is false.

4. A+B ---> C
Which of the following would not affect the reaction rate of this irreversible reaction?
a. decreasing A
b. increasing B
c. adding a catalyst
d. removing C
e. increasing temperature

5. If Cs metal was exposed to light of a certain minimum frequency called the threshold frequency, electrons are ejected from the surface of the metal. What is the correct term for this phenomenon?
a. quantum theory
b. photoelectirc effect
c. bohr effect
d. poto fluorescent effect
e. tunneling effect
=> answer is b, but how about a? why not a?

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[bigstix808]

1. another name of "electrolytic cell " is "elecrochemical cell"???
are these two exactly the same?

false, electrochemical cells are the same as voltaic or galvinic
http://en.wikipedia.org/wiki/Electrochemical_cell

2. In the molecule, H3C6H5O7, it gives three protons in the solution. How can we know this molecule gives three proton without drawing molecular structure?

the fact they wrote the molec formula with H3 first is pretty good dead give away (as opposed to C6H8O7). if it was just an empirical formula you would really have no way of knowing

3. "A 3d orbital can hold a maximum of 10 electorns."
Is this statement true? I think it's ture, but answer is false.

must be a play on the "definition" of orbital. any single orbital can only hold 2 e- (s, p, d, or f) - period; the d-subshell can hold 10 (max#e- per subshell = 4ℓ + 2)

4. A+B ---> C
Which of the following would not affect the reaction rate of this irreversible reaction?
a. decreasing A
b. increasing B
c. adding a catalyst
d. removing C
e. increasing temperature

removing C; rxn in irreversable. kind of like saying if you remove CO2 you'll make something burn faster. rate = k [A]^x ^y (C is no where to be found); catalyst will increase k, not K; increasing temp always increases k

5. If Cs metal was exposed to light of a certain minimum frequency called the threshold frequency, electrons are ejected from the surface of the metal. What is the correct term for this phenomenon?
a. quantum theory
b. photoelectirc effect
c. bohr effect
d. poto fluorescent effect
e. tunneling effect
=> answer is b, but how about a? why not a?

quantum theory just states that difference between energy levels of an atom are discrete quantities, and in order for an e- to move between those energy levels, that energy level's exact amount of energy must be absorbed or expelled in order to affect the e-. the answer can not be A because it is quantum theory that explains why the photoelectric effect works.


btw, i notice that you post a good amount of questions on here...where are they coming from??? i like em!

i'm taking the test on monday so sorry for any lengthy answers

 

[userah]

i recognize a few questions from dat destroyer. not sure if all of them are from there though.

 

[ippie]

thank you for your kind explanation. the questions I posted here are from DAT destroyer, Kaplan and some my class notes. I hope it helps you.