A few questions about 2009 ADA test

[drill-and-fill]

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I just got a few questions about the 2009 ADA test that I took this morning... Overall it wasnt bad but damn, RC was crazy! Ive never seen such confusing questions or answer choices in any other RC practice materials; it was like they were deliberately trying to mess with your head lol. I really hope the actual RC wont belike this. Now on to the questions...

Question 82. Each of the following is a polymer except for one. Which one?

Protein
Plastic
Rubber
Glycogen
Petroleum

Why is the answer petroleum? Can someone please explain?

Question 91. Which of the following techniques can be used to separate non-volatile substances?

TLC
gas liquid chromotography
Sublimation
Distilation
Steam distilation

Answer is TLC

I had no idea about this one... I just guessed. What does it mean by 'non-volatile' substances?

Question 99... Something about the multistep synthesis of antispamodic spasmolytol...

Can someone explain how or why the answer is D instead of A?

Thanks in advance !

 

[Kingsta2426]

I just got a few questions about the 2009 ADA test that I took this morning... Overall it wasnt bad but damn, RC was crazy! Ive never seen such confusing questions or answer choices in any other RC practice materials; it was like they were deliberately trying to mess with your head lol. I really hope the actual RC wont belike this. Now on to the questions...

Question 82. Each of the following is a polymer except for one. Which one?

Protein
Plastic
Rubber
Glycogen
Petroleum

Why is the answer petroleum? Can someone please explain?

Question 91. Which of the following techniques can be used to separate non-volatile substances?

TLC
gas liquid chromotography
Sublimation
Distilation
Steam distilation

Answer is TLC

I had no idea about this one... I just guessed. What does it mean by 'non-volatile' substances?

Question 99... Something about the multistep synthesis of antispamodic spasmolytol...

Can someone explain how or why the answer is D instead of A?

Thanks in advance !

-RC isin't that bad on the real DAT but its not much easier.

-Protein is a polymer of amino acids
-Plastic/Rubber are known polymers I learned this in Ochem
-Glycogen is a polymer of glucose

-Non-volatile substance means it can't vaporize, and therefore all distillations and sublimation would be worthless since they deal with the gas phase.

-Question 99 makes absolutely no sense, don't worry about it. A professor on here even said it was ******ed.

 

[ktran17]

Q1 :
A polymer is a substance that has repeating units (monomers)
Protein -> amino acids
plastic> carbon chain
rubber> carbon chain (probably other repeating stuff)
glycogen> alpha glucose
petroleum: aka crude coil and is a mixture of minerals, sand, and other stuff. basically, its a heterogeneous mixture, not a polymer

Q2: a non-volatile substance, is something that has a high boiling point, and therefore cant be turned into the vapor form easily

GLC, sublimation, distillation, and steam distillation: separates based off vapor pressure

TLC: separates based off polarity and is therefore the answer

 

[drill-and-fill]

Thanks guys.

Another one; ionic compounds are not good conductors of electricity in solid states. But are they good conductors in aq state? Or, are metals the only good conductors of electricity?

 

[ktran17]

They can conduct electricity in the aqueous state.

Also, ionic solids can also conduct in the molten state.

Ionic compounds are able to conduct electricity in the aq and molten state because the ions are free to move around.

source: chad's videos 😀