"Good morning class." Mr Choi enter the class and greet his students.

"Morning Mr Choi." The students greet him.

 

"He is our Chemistry teacher." Student who sit behind told me.

I slightly turned my head back, he gave me a smile. I just gave him small nod and a little smile, and turned my head to the front.

"Well, I heard you guys had new student." 

Now all the students head turned to my direction. Great enough, now he must request me to introduce myself again.

"Oh..I'm your chemistry teacher Mr. Choi." Mr Choi introduce himself.

I just smile and bowed. 

"Kim Yoo Jung." I introduce myself before I sit.

"Okay. Nice to meet you. Okay. Today we will had quiz." Mr Choi said, and causes whole class to groan including me.

Seriously? What's up with the sudden quiz?. 

I tried my best to let my brain jogged back whatever I had studied last few months. I received the question paper.

"And no cheating, no copying, no co-operating with your friends, because I will not compromising with cheater. Okay?" 

Look like Mr Choi took this exam really serious. 

I look and read the question in front of me. 

1) Which of the following molecules and ions are nucleophilic?

A CH4 B H2O C BH3 D H2C=CH2 E OH(–) F Br(+) G NH3 H Br(–)

2) Changes in Oxidation States

Consider reactions 1 through 6. Those carbon atoms undergoing change, as part of a functional group, are colored (red and blue). In the cases shown, each carbon atom has either been reduced or oxidized. Your job is to identify the change in oxidation state that has occurred for each of the colored carbons.

Reaction Red Carbon Blue Carbon 1. CH3CH=CH2 Br2

  CH3CHBrCH2Br Reduced
Oxidized Reduced
Oxidized 2. CH3CH=CH2 (i) B2H6

(ii) H2O2 , NaOH CH3CH2CH2OH Reduced
Oxidized Reduced
Oxidized 3. CH3CH2CH=O NaBH4

  CH3CH2CH2OH Reduced
Oxidized   4. CH3CH2CH=O Ag(+)

H2O , pH>8 CH3CH2CO2H Reduced
Oxidized   5. CH3COCH2CO2H Heat

  CH3COCH3
+
O=C=O Reduced
Oxidized Reduced
Oxidized 6. H2C=C(OH)C2H5 tautomerization

  H3CCOC2H5 Reduced
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