Qualification > Sciences

ALL CIE CHEMISTRY DOUBTS HERE !!

<< < (48/142) > >>

$!$RatJumper$!$:
S06 Q 10, 12, 17, 21, 25

Thank you kindly :)

birchy33:
You guys have been terrific and I hate to bundle you with more questions  ... but  ;D
O/N 09 QP1 variant 2

Q20
Q23
Q27

and to my much embarrassment ... Q1: I know its either A or D but I've completely forgot how to pick which one.

Cheers brudas.

Master_Key:

--- Quote from: birchy33 on November 18, 2010, 01:04:56 am ---You guys have been terrific and I hate to bundle you with more questions  ... but  ;D
O/N 09 QP1 variant 2

Q20
Q23
Q27

and to my much embarrassment ... Q1: I know its either A or D but I've completely forgot how to pick which one.

Cheers brudas.

--- End quote ---

O/N 09 QP1 Variant 2.

Q1. Answer is D.

It is because 0.2 Moles of HC burn to give 35.4 g of CO2.

So, RFM of CO2=(12+(16*2)=44 g.

35.4/44 = 0.8

0.8 = 0.2
?    = 1

0.8/0.2=4

This is the simplest method. We get 4 Carbon atoms in one molecule of HC.

Do the Same with Water and we will get 8 Hydrogen atoms.

So the formula is C4H8

Master_Key:

--- Quote from: birchy33 on November 18, 2010, 01:04:56 am ---You guys have been terrific and I hate to bundle you with more questions  ... but  ;D
O/N 09 QP1 variant 2

Q20
Q23
Q27

and to my much embarrassment ... Q1: I know its either A or D but I've completely forgot how to pick which one.

Cheers brudas.

--- End quote ---

O/N 09 QP1 Variant 2.

Q23. Answer is A.

The diagram shows 2 double bonds between C=C atoms. These are the bonds which are broken and Hydrogen or Bromine added. The C=O will not break. Both the double bonds break and form a single bond C-C. 2 Hydrogen atoms are bonded with two Carbon atoms. There are four carbon atoms so 4 Hydrogen atoms.

This gives to 2 moles of both substances as both exist as diatomic molecules.

elemis:

--- Quote from: $!$RatJumper$!$ on November 17, 2010, 09:37:05 pm ---S06 Q 10, 12, 17, 21, 25

Thank you kindly :)

--- End quote ---

Question 17

Chlorine displaces Iodine from the salt. So the Iodide anions lose electrons to chlorine i.e. they are oxidised.

Navigation

[0] Message Index

[#] Next page

[*] Previous page