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Chemistry: Post your doubts here!

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The products obtained by cracking an alkane, X, are methane, ethene and propene.
The mole fraction of ethene in the products is 0.5.
What is the identity of X?
A C6H14 B C8H18 C C9H20 D C11H24
how do u get the answer?
 
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How many isomers with the formula C5H10 have structures that involve π bonding?
A 3 B 4 C 5 D 6
this too is confusing!!:confused:
 
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2 When a sample of a gas is compressed at constant temperature from 1500 kPa to 6000 kPa, its
volume changes from 76.0cm3 to 20.5cm3
Which statements are possible explanations for this behaviour?
1 The gas behaves non-ideally.
2 The gas partially liquefies.
3 Gas is adsorbed on to the vessel walls

why is 1 only correct...?it might be liquified as well??? so 2 should also be correct ..why isnt it???
 
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2 When a sample of a gas is compressed at constant temperature from 1500 kPa to 6000 kPa, its
volume changes from 76.0cm3 to 20.5cm3
Which statements are possible explanations for this behaviour?
1 The gas behaves non-ideally.
2 The gas partially liquefies.
3 Gas is adsorbed on to the vessel walls

why is 1 only correct...?it might be liquified as well??? so 2 should also be correct ..why isnt it???

compressing at constant temp will never liquify any gas... you have to cool the cylinder as well for liquifying... else the cylinder will blast away....
 
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The products obtained by cracking an alkane, X, are methane, ethene and propene.
The mole fraction of ethene in the products is 0.5.
What is the identity of X?
A C6H14 B C8H18 C C9H20 D C11H24
how do u get the answer?

is the answer B...?? if yes then i think i can explain u easily..if not then... ... ... :)
 
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Use of the Data Booklet is relevant to this question.
Which element is likely to have an electronegativity similar to that of aluminium?
A barium
B beryllium
C magnesium
D strontium


why is it B....how?

Are you sure it's B and not C? I thought the answer to this question was C, since Mg is in the same period, and according to the book, their electronegativity is similar. :/
 
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oh goog... look.. we have 3 products.. ethene methane and propene...

if i mole is produced by cracking, then o.5% will be of ethene(as mentioned in the q) then 0.25 of propene and .25 of methane is produced... .25+.25+.5=1...

to convert .25 into proper fraction, we need to multiply it by 4 to bring it to a whole number... by doing this.. we will get 1 mole of propene, 1 mole of methane and 2 moles of ethene(.5*4).. no of Carbons now we have are 8 all together... so B is the answer...
 
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Are you sure it's B and not C? I thought the answer to this question was C, since Mg is in the same period, and according to the book, their electronegativity is similar. :/
yup me too .... thought Mg but it is B- beryllium
 
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oh goog... look.. we have 3 products.. ethene methane and propene...

if i mole is produced by cracking, then o.5% will be of ethene(as mentioned in the q) then 0.25 of propene and .25 of methane is produced... .25+.25+.5=1...

to convert .25 into proper fraction, we need to multiply it by 4 to bring it to a whole number... by doing this.. we will get 1 mole of propene, 1 mole of methane and 2 moles of ethene(.5*4).. no of Carbons now we have are 8 all together... so B is the answer...

thxx ... tht was good was explanation.......:)
 
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do you know have any concept about diagonal relationship of periodic table...???
its about the thing that the first element in the group is in some cases similar in reactions to the elements of the group before it... for example, Be is similar in ways to the Alkali metals...
 
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