POST YOUR BIO AND CHEM PAPER 1 DOUBT HERE !!!!

[natsume hyuga]

Always in carboxylic acids ,in reactions,the OH is removed but from alcohol the H only.
Take for example soap formation

ah right thnx x)

 

[Skynox]

ah right thnx x)

Anytime ....Also carboxylic acid and NAoh is an acid base reaction while the most alcohol doesn't react with NaOh…

 

[natsume hyuga]

16 Three reactions used in the manufacture of sulphuric acid are shown.
1 S + O2 → SO2
2 2SO2 + O2 → 2SO3
3 SO3 + H2O → H2SO4
Which of these reactions are redox reactions?
A 1 only
B 3 only
C 1 and 2 only
D 2 and 3 only
answer is c. Anyone help tell me why?

 

[svenas]

16 Three reactions used in the manufacture of sulphuric acid are shown.
1 S + O2 → SO2
2 2SO2 + O2 → 2SO3
3 SO3 + H2O → H2SO4
Which of these reactions are redox reactions?
A 1 only
B 3 only
C 1 and 2 only
D 2 and 3 only
answer is c. Anyone help tell me why?

which yr is this q?

 

[thats_me]

16 Three reactions used in the manufacture of sulphuric acid are shown.
1 S + O2 → SO2
2 2SO2 + O2 → 2SO3
3 SO3 + H2O → H2SO4
Which of these reactions are redox reactions?
A 1 only
B 3 only
C 1 and 2 only
D 2 and 3 only
answer is c. Anyone help tell me why?

as in 1 and 2 electron transfer takes place but not in 3

 

[natsume hyuga]

as in 1 and 2 electron transfer takes place but not in 3

i know but show how, the equations please?

 

[Skynox]

i know but show how, the equations please?

In equation 1 : Sulfur is oxidized since it gained oxygen..Oxygen molecules are reduced into atoms.
In equation 2 : Same as the previous one
In equation 3 :Sulfur trioxide is oxidized but the oxidation state of oxygen remained constant.
So equation 1,2 there was an oxidation and reduction due to the change in the Oxidation state of oxygen molecule
In equation 3, only oxidation took place
SO3 oxidized and H2o remained..
That way we could consider any gain of oxygen as a redox reaction not just oxidation when speaking about atoms reacted with molecules..

 

[Razo513]

help plz ?? can someone explain how is the answer is B ? :S

 

[Skynox]

help plz ?? can someone explain how is the answer is B ? :SView attachment 12068

Consider the equation where
The more reactive halogen displaces the less reactive one.Since,iodine is nearly the least reactive so it can't displace any halogen ,except At which is rarely used,..
So X2 is Chlorine..
Consider chlorine is passed through aqueous potassium iodide,the result will be potassium chloride and iodine(in solution)..
Potassium iodide is colourless and iodine solution is yellow brown.

 

[L-Girl]

would I have to study the whole syllabus again?

 

[L-Girl]

can someone help with question 38, june 2006 Bio?
i don't get why it is C

 

[saroooor]

help plz ?? can someone explain how is the answer is B ? :SView attachment 12068

Consider the Y- is a bromide it got displaced by chlorine into a chloride and Bromine . From Colourless to brown . I believe so .....

 

[Skynox]

can someone help with question 38, june 2006 Bio?
i don't get why it is C

The factor which had the least effect is the elimination of predators..Since,humans don't have predators

 

[saroooor]

Now he

can someone help with question 38, june 2006 Bio?
i don't get why it is C

He is asking the least effect , that did not lead too much of growth . You would eliminate B & D . you're left with A & C !!! C is more Logic . First I was like A then I said that C is more logic to eleminate predators didnot have great effect on the growth .

 

[saroooor]

Now he
He is asking the least effect , that did not lead too much of growth . You would eliminate B & D . you're left with A & C !!! C is more Logic . First I was like A then I said that C is more logic to eleminate predators didnot have great effect on the growth .

And also population means same species and I think they mean Humans .... Did you get it ?

 

[Skynox]

And also population means same species and I think they mean Humans .... Did you get it ?

Word population is us..Humans don't usually have predators..

 

[saroooor]

Word population is us..Humans don't usually have predators..

Yeah and also Population means same species and World population so they mean humans , right ?

 

[L-Girl]

ooooh thanks a lot, now I get it thanks again

 

[Skynox]

Yeah and also Population means same species and World population so they mean humans , right ?

Exactly.

 

[saroooor]

Nov. 05 Question number 19 is it D Because zinc carbonate and zinc hydroxide are insoluble ?