GC questions from destroyer

[Bigbirdo]

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2. For question 114, I thought the answer was B because CF4 give the strongest dipole-dipole interaction. However, the answer is C. Is that because CF4 have all its dipoles canceled out, so we choose the molecule with the greatest van der waal force?

3. For question 201, can someone explain to me that when potential energy and kinetic energy of a chemical substance do increases or decreases?

4. For question 153, why can’t the answer be B since Ag is also a transitional metal?

 

[SafetyDog]

2. For question 114, I thought the answer was B because CF4 give the strongest dipole-dipole interaction. However, the answer is C. Is that because CF4 have all its dipoles canceled out, so we choose the molecule with the greatest van der waal force?

3. For question 201, can someone explain to me that when potential energy and kinetic energy of a chemical substance do increases or decreases?

4. For question 153, why can’t the answer be B since Ag is also a transitional metal?

2. Can't help you

3. Think of heat as energy, so you are giving off energy in an exothermic reaction which means you are going from a higher state of energy to a lower state of energy. With a lower state of energy, you have less overall energy and therefore, less potential energy.

4. Well Ag is the element silver, and probably has the color of silver. If you've seen oxidized copper in real life, you'd know it's a tealish / bluish color.

 

[Bigbirdo]

2. Can't help you

3. Think of heat as energy, so you are giving off energy in an exothermic reaction which means you are going from a higher state of energy to a lower state of energy. With a lower state of energy, you have less overall energy and therefore, less potential energy.

4. Well Ag is the element silver, and probably has the color of silver. If you've seen oxidized copper in real life, you'd know it's a tealish / bluish color.

For number 3, the answer says that kinetic energy increases and potential energy increases.If that means the kinetic energy of the surrounding increases (heat added), and the potential energy of the chemical substance decreases. What about the kinetic energy of the substance and the potential energy of the the surrounding? increase or decrease?

 

[Xo1991]

highest surface tension usually goes to one with highest boiling point. so first thing is to look for hydrogen bonding. none of those molecules have hydrogen bonding, so next you look at van der waals forces. Van der waals goes by molecular weight/size. CI4 is clearly the biggest, so it will have the highest surface tension and highest boiling point.

 

[mostprecious]

It would be helpful if you wrote down the whole problems b/c I don't have Destroyer in hand,

but for #3, write out the electron configuration for both Cu and Ag. You will notice that Ag has all of its electron orbits filled, while Cu has one empty. That empty orbital means it's not as stable and so energy can be released/deposited when photons hit it to cause electrons to become excited, releasing energy as colored light. (if I remember correctly) So just know that if you have an empty orbital in a transition metal, then color is given off.

 

[mostprecious]

It would be helpful if you wrote down the whole problems b/c I don't have Destroyer in hand,

but for #3, write out the electron configuration for both Cu and Ag. You will notice that Ag has all of its electron orbits filled, while Cu has one empty. That empty orbital means it's not as stable and so energy can be released/deposited when photons hit it to cause electrons to become excited, releasing energy as colored light. (if I remember correctly) So just know that if you have an empty orbital in a transition metal, then color is given off.

 

[Ellabelle]

Which ediction of Destroyer are you using?

 

[hope_to_match]

can you post the problems?

 

[Bigbirdo]

can you post the problems?

The reason I didn't post the whole problem is that I saw a post by orgoman saying that posting any whole problems from destroyer is not allowed....it would make things much easier if I can just post the problems.

 

[Bigbirdo]

Which ediction of Destroyer are you using?

I used the 2012 edition.

 

[Minion]

You think someone is going to compile all the destroyer questions to make their own free book ? lol

 

[Bigbirdo]

It would be helpful if you wrote down the whole problems b/c I don't have Destroyer in hand,

but for #3, write out the electron configuration for both Cu and Ag. You will notice that Ag has all of its electron orbits filled, while Cu has one empty. That empty orbital means it's not as stable and so energy can be released/deposited when photons hit it to cause electrons to become excited, releasing energy as colored light. (if I remember correctly) So just know that if you have an empty orbital in a transition metal, then color is given off.

This is question 201
201. Which statement is false?
a. If a reaction is exothermic, the system evolves heat to the surroundings
b. During an exothermic reaction, a chemical substance increases in potential energy
c. During an endothermic reaction, the temperature of the surrounding is lowered
d. B and C
e. A and B.

The answer is B. According to the answer, a chemical substance decreases in potential energy in an exothermic reaction. But it also say "we see an increase in kinectic energy" I dont get kinetic energy of what? The surrounding or the substance?

Here is my ultimate question (increases or decreases?)
In a endothermic reaction, kinetic energy of the system (?), kinetic energy of the surrounding (?), potential energy of the system (?), potential energy of the surrounding (?)

In a exothermic reaction, kinetic energy of the system (?), kinetic energy of the surrounding (?), potential energy of the system (?), potential energy of the surrounding (?)