Chemistry: Post your doubts here!

[periyasamy]

I got to go out know.But generally what u need to do is this.First form a half equation for for pb ion n bromide ion.U will then get the ratio.So then u find the mole of pb ion using the mass given.Finally with the ration value,u can get the value of bromine.

u got it?

 

[salvatore]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Chemistry (9701)/9701_w09_qp_51.pdf
Could someone please help me with qn no. 2(a) of this paper? To calculate the mass of zinc, why do we have to do (B - D) and not (B - A)?
Thanks

 

[periyasamy]

Hi guys need help here?
Ans is c.Thank u.

 

[periyasamy]

Hai guys.Anyone have idea about this question.Just want to ask why option 3 is rejected .Thanks guys.

 

[Abhi Mevawala]

Guys,I dont really get this question.anyone have a clue?

is the ans B?

 

[Abhi Mevawala]

i

Need help with this questionView attachment 33027 . Thank you in advance.

is the ans d?

 

[Abhi Mevawala]

Hi guys need help here?
Ans is c.Thank u.

hey see BF3 is trigonal planer so option B and D are eliminated
aftr the reaction Boron has a hybridisaton of sp3 tht is tetrahydral lyk CH4 so it have shape lyk it
thrfor the ans is C

 

[Abhi Mevawala]

Hai guys.Anyone have idea about this question.Just want to ask why option 3 is rejected .Thanks guys.

the ans here is D
becoz the second option is wrong as when HBr reacts with any alkene H and Br both go on different carbon atoms nt the same one

 

[Abhi Mevawala]

my doubtzz

 

[Abhi Mevawala]

got few more

 

[Abhi Mevawala]

 

[periyasamy]

the ans here is D
becoz the second option is wrong as when HBr reacts with any alkene H and Br both go on different carbon atoms nt the same one

Sorry bro,i rechecked it but the answer is B that is option 1 and 2 rite.Thanks a lot.

 

[periyasamy]

my doubtzzView attachment 33040View attachment 33041View attachment 33042

For 1st question.

 

[Abhi Mevawala]

watzz the ans.............

 

[periyasamy]

ans is c.Rite?

 

[Abhi Mevawala]

yyup bt hw?

 

[periyasamy]

Check the file,i sent...First findnthe mole of co2.Then using the formula judge the no of mole of the aluminium compound.Then u will get the molar mass by using the mole formula.Finally u will get 144.Try each of the 4 options n u will get c.Hope it helps.

 

[Abhi Mevawala]

thnxx
hey can u solv this

 

[periyasamy]

thnxx
hey can u solv thisView attachment 33053

Is the answer a?

 

[snowbrood]

my doubtzzView attachment 33040View attachment 33041View attachment 33042

for q35
redox reaction mean a chemical reaction in which the oxidation state of the element changes here N is reduced.
NaOcl is a bleaching solution that u have to study in group 7 halogens
nacl has an halogen that reacts with silver nitrate so A is the answer