Author Topic: CHEM AND BIO HELP AND TIPS HERE  (Read 350922 times)

Offline someone

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2205 on: May 25, 2010, 12:17:35 am »
can any1 explain this HAMZ u dere

noble gas is the last group
it always have 8 electrons in the last shell, therefore answer is B
bcause it has 8 electrons, it's stable and is unreactive

Offline High-R

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2206 on: May 25, 2010, 12:42:22 am »
oh sorry nidzz i was away!!
ya someone's right...its last shell has 8 electrons ..it has a structure like neon!!

Offline jellybeans

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2207 on: May 25, 2010, 03:44:07 am »
... help pleaseeee
You said I must eat so many lemons cause I am so bitter.

Offline Raywin

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2208 on: May 25, 2010, 03:53:31 am »
;D

Offline jellybeans

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2209 on: May 25, 2010, 04:00:11 am »
You said I must eat so many lemons cause I am so bitter.

holtadit

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2210 on: May 25, 2010, 04:14:10 am »

Offline jellybeans

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2211 on: May 25, 2010, 04:15:30 am »
You said I must eat so many lemons cause I am so bitter.

holtadit

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2212 on: May 25, 2010, 04:17:12 am »
See the number (VII) thats written after the word dichromate ?? Thats the OXIDATION state.

If that number changes then the oxidation state changes too.


BUT in this case it hasnt so the OXIDATION STATE IS THE SAME.

SO the answer is C or D

Next EXCESS K(OH) was added so the pH for an alkali is 12ish.  So the pH would INCREASE


ANSWER is D


Which year is this from ?

Offline jellybeans

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2213 on: May 25, 2010, 04:21:54 am »
See the number (VII) thats written after the word dichromate ?? Thats the OXIDATION state.

If that number changes then the oxidation state changes too.


BUT in this case it hasnt so the OXIDATION STATE IS THE SAME.

SO the answer is C or D

Next EXCESS K(OH) was added so the pH for an alkali is 12ish.  So the pH would INCREASE


ANSWER is D


Which year is this from ?

OHOHHHHHOH, thankss  ;D
uhmm, M/J 08 :)
« Last Edit: May 25, 2010, 04:25:50 am by jellybeans »
You said I must eat so many lemons cause I am so bitter.

Offline WARRIOR

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2214 on: May 25, 2010, 04:31:15 am »
hard one

answer is A ?why
NO secrets to SUCCESS , it is the result of 1.HARD WORK 2.GOOD PREPARATION 3.LEARNING FROM FAILURE
But it ain't how hard you hit; it's about how hard you can get hit, and keep moving forward-Balboa

Offline jellybeans

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2215 on: May 25, 2010, 04:33:24 am »
2 more...

! Q11 & Q39

for q39, answer's D, but i thought carboxylic acids & alcohols have the same number of H? since its CnH2n+1OH and CnH2n+1COOH

:S helpppppp pleasee !!!!! :( :( :( :(
exams in an hourrrrr, hahahahahaha..
« Last Edit: May 25, 2010, 04:37:44 am by jellybeans »
You said I must eat so many lemons cause I am so bitter.

Offline WARRIOR

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2216 on: May 25, 2010, 04:47:26 am »
2 more...

! Q11 & Q39

for q39, answer's D, but i thought carboxylic acids & alcohols have the same number of H? since its CnH2n+1OH and CnH2n+1COOH

:S helpppppp pleasee !!!!! :( :( :( :(
exams in an hourrrrr, hahahahahaha..

u said the asnwer is D

thats an ETHENE AND CARBOXYLIC ACID

it works ^

andwer for 11 is D also
...you have to do the ocmubstion reaction and balance
NO secrets to SUCCESS , it is the result of 1.HARD WORK 2.GOOD PREPARATION 3.LEARNING FROM FAILURE
But it ain't how hard you hit; it's about how hard you can get hit, and keep moving forward-Balboa

Offline WARRIOR

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2217 on: May 25, 2010, 04:55:13 am »
why is answer A

isnt smaller give it a larger S.A?

NO secrets to SUCCESS , it is the result of 1.HARD WORK 2.GOOD PREPARATION 3.LEARNING FROM FAILURE
But it ain't how hard you hit; it's about how hard you can get hit, and keep moving forward-Balboa

Offline jellybeans

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2218 on: May 25, 2010, 04:56:05 am »
u said the asnwer is D

thats an ETHENE AND CARBOXYLIC ACID

it works ^

andwer for 11 is D also
...you have to do the ocmubstion reaction and balance

.. ohhhh, then why doesnt it work for ethanoic acid and ethanol??? both has 6 Hydrogen atoms aswell/? :( :( :( no?
and for Q11, it's B.
You said I must eat so many lemons cause I am so bitter.

holtadit

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Re: CHEM AND BIO HELP AND TIPS HERE
« Reply #2219 on: May 25, 2010, 05:00:10 am »
why is answer A

isnt smaller give it a larger S.A?



Your correct; the answer you gave is from a teacher's mark scheme remember that.