Chemistry: Post your doubts here!

[nehaoscar]

??

 

[Mathemagical]

View attachment 54419
2Mg + 2H2O = 2MgOH + H2

Mg (24.3) + O (16) + H (1) = 41.3 Mr ... so shouldn't A be wrong?

But then it's D ... is it slightly soluble then?

Magnesium burns in steam to produce white magnesium oxide and hydrogen gas.
http://tinyurl.com/nlg5ujc

 

[nehaoscar]

Is it possible to form such an alkene for C? I think it's not because the answer is B ... but could someone tell me why it's not possible?

 

[qwertypoiu]

View attachment 54417
??

C, since CO2 is not polar

 

[Mathemagical]

View attachment 54421
Is it possible to form such an alkene for C? I think it's not because the answer is B ... but could someone tell me why it's not possible?

It is possible. However, you can only form 2 different types since it's symmetrical.

Option B involves 4 different alkenes due to cis-trans isomerism.

 

[qwertypoiu]

The answer is A

I believe that phosphoric acid is a weak acid, so is the phosphorous acid strong acid?

I think Phosphoric acid is formed when P4O10 is put in water. It's considered strong I think, although it's pH is 3.
At least it's not 4-6

 

[princess Anu]

Is it A?

No it's C

 

[nehaoscar]

C, since CO2 is not polar

Could you please explain a bit more?
I mean like the others are not polar either right?

 

[nehaoscar]

Q38..

https://sg.answers.yahoo.com/question/index?qid=20120820030922AAFoXOO

 

[Xaptor16]

View attachment 54323
For optical isomerism, you need a carbon with a chiral center ( 4 different substituents on the C)
As you can see only 1,2 and 3 have a chrial carbon (marked red)
So it is B

It burns readily, so there will be a high concentration of CO2 in the equilibrium mixture. Therefore, applying the formula for equilibrium constant, we can deduce that the value is likely to be high.

thankyou so much

 

[ciephobia]

http://maxpapers.com/wp-content/uploads/2012/11/9701_s14_qp_11.pdf
i need help with question 8^. why can't the temperature be 398k?
thanks in advance.

 

[The Sarcastic Retard]

http://maxpapers.com/wp-content/uploads/2012/11/9701_s14_qp_11.pdf
i need help with question 8^. why can't the temperature be 398k?
thanks in advance.

Exothermic reactions favour low temeperatue and low Ph till I know.. Is it A?

 

[nehaoscar]

How to do this?

 

[ciephobia]

Exothermic reactions favour low temeperatue and low Ph till I know.. Is it A?

yes it is A.
thankyou

 

[nehaoscar]

http://maxpapers.com/wp-content/uploads/2012/11/9701_s14_qp_11.pdf
i need help with question 8^. why can't the temperature be 398k?
thanks in advance.

Exothermic reactions favour low temeperatue and low Ph till I know.. Is it A?

I think that Exothermic reactions favour low temeperature applies only when in equilibrium
So in normal reactions rate will be reduced as temperature is decreased?

 

[The Sarcastic Retard]

yes it is A.
thankyou

I am not sure for pH.. wait for some1 to answer

 

[ciephobia]

View attachment 54426
How to do this?

hey i found this explanation on a thread.

 

[ciephobia]

I think that Exothermic reactions favour low temeperature applies only when in equilibrium
So in normal reactions rate will be reduced as temperature is decreased?

well yes, this sounds good.

 

[ciephobia]

I am not sure for pH.. wait for some1 to answer

ph is 7, that is neutral.

 

[nehaoscar]

hey i found this explanation on a thread.

But then how do you know that definitely 0.25 of propene and 0.25 of methane are formed?
Like it could be 0.1 and 0.4 or anything right?