Multiple Choice Answers (1 Viewer)

[xeriphic]

Question 9 is weird. I originally got A through the mole method, using the O3 molecule. When I checked it, I used the NO molecule instead, and got an answer that rounded to 50. As the question states the maximum amount, I changed it to D.

lol I thought same as you, apparently though ozone is a limiting reagent in this case, and can only produce up to 0.39L or whatever

 

[The Bograt]

Your right about ozone being the limiting factor, but you prolly used the wrong mole of gas volume.

Just checked it, you are right....
Why in hell did I use 24.71? It isn't even a value for ANY OF THEM!

Damn

 

[xeriphic]

And also question 12. With the pictures there I immediately though ammonia and water but it wasn't an option.

I don't think ammonia and water react forms coordinate covalent bonds, throught each do react with hydrogen ion to form one

 

[Gesus]

Question 9 is weird. I originally got A through the mole method, using the O3 molecule. When I checked it, I used the NO molecule instead, and got an answer that rounded to 50. As the question states the maximum amount, I changed it to D.

LOL, the fact that there was more NO than O3, suggested that O3 was a limiting factor, and hence, A

 

[Bridget]

Question 9 is weird. I originally got A through the mole method, using the O3 molecule. When I checked it, I used the NO molecule instead, and got an answer that rounded to 50. As the question states the maximum amount, I changed it to D.

Yeah I got A through using mole calculations, and you're right, it says MAXIMUM. But using the ozone molecule, there's less moles..... so therefore less to react. The reaction can only take place until all the ozone is used up, then can't happen anymore.... so I still put A.

 

[The Bograt]

hahaha if 12 is C then that is awesome cause I guessed that

 

[lukebennett]

1a
2a
3c
4b
5c
6d
7d
8d
9a
10c
11a
12c
13b
14a
15b

 

[chelseafan]

1) A.. obvious esterification
2) A... the moral of the story is always to help the environment
3) B... Goes green-blue in flame test
4) B... Quite obviously isomers
5) C... I guess its in the book
6) D... self explanatory
7) D... increase in pH by 3 means decrease in [H+] by 1000.
8) D... troposphere, stratosphere, mesosphere, thermosphere.
9) A... The ozone gas is limiting agent. Only 0.015 moles present V=0.015 X 22.71
10) C... Reaction is exothermic so low temp increases yield of products. there is 2 moles of gas on reactants side and 1 mole of gas on products. high pressure increases yeild of products.
11) A... As pentanol is smallest it will arrive first then hexanol is next smallest and arrives second thus the peak is for hexanol
12) C... Also instinctively though ammonia and water but ammonia and hydrogen flouride was next best guess.
13) C... from formula H=mCT... u get change in temp= mass times C divided by molar heat of combustion. You have to convert the mass of propanol burnt into moles of propanol burnt. n=m/M n=0.6/60 n=0.01 moles. When you convert the molar heat of combustion back into joules instead of Kj u get a result for change in temperature = 24.2...then u have to add it to original temperature and u get 45.2 degrees, C
14) A... The more reactive metal gets oxidised easier. And oxidation occurs at the anode ( negative terminal) so most reactive metal was z then y then Pb then x
15) B... I cannot really comment on this one im very iffy, but i do have faint recollection of the Lead plate being the anode , and i think the anode is the negative terminal.

That's my two cents.

 

[euphoric]

How come 11 is (a) 1-hexanol?

1-octanol takes the longest to destect ... coz there's 8 carbons
1-heptanol is the second longest... so shouldnt it be (c) 1-heptanol?

if u re-read the question it said the smaller the molecular weight the more quickly the compound is detected.

hence X is
A) 1-hexanol.

 

[mushroom_head]

ok~ here's mine:

1A
2A
3B
4B
5C
6D
7D
8D
9A
10C
11A
12A <<how do u do this??????
13C
14A
15B

 

[Managore]

For the battery Q (15 I think) I just imagined putting a battery into my digital camera, and which side was +, which was -... I think it worked

 

[lukebennett]

with 12 you had to notice that HF neutralises NH3 to form NH4+ which has a coordinate bond

 

[kheir]

chemistry wat is chemistry??????

 

[wind]

I did the stupidest things for the MC!

Changed the answer from isomers to allotropes (crossed out the answer even for question 4) and forgot to add the difference in question 13! So I had 24.2 degress celsius instaed of 45.2!!

*sigh*

 

[withoutaface]

12 the trick was to know that methane is inert.

 

[The Bograt]

12 the trick was to know that methane is inert.

My 'trick' was to guess
It worked though

 

[aim54x]

how do u guys remember wat u wrote???

 

[Gesus]

14) A... The more reactive metal gets oxidised easier. And oxidation occurs at the anode ( negative terminal) so most reactive metal was z then y then Pb then x
15) B... I cannot really comment on this one im very iffy, but i do have faint recollection of the Lead plate being the anode , and i think the anode is the negative terminal.

That's my two cents.

14, it says in order of INCREASING oxidation of metals... so i put D, im still iffy about it but im becoming more confident

15. simply look to the left, you should have known either carbon rod = cathode, or zinc case = anode, and from there you should know anode = negative terminal for galvanic cells

 

[euphoric]

I did the stupidest things for the MC!

Changed the answer from isomers to allotropes (crossed out the answer even for question 4) and forgot to add the difference in question 13! So I had 24.2 degress celsius instaed of 45.2!!

*sigh*

hmmz howd you get 24.2?
none of my answers even matched the mc answers ><

 

[Managore]

Eupho, theres a thread dedicated to Q13, look at that.