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Chemistry: Post your doubts here!

Hassan Ali Abid

Hassan Ali Abid

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chocolate_girl said:
  1. understand, in simple terms, the concept of electronegativity
    and apply it to explain the properties of molecules such as bond polarity (3h), the dipole moments of molecules (3j), the behaviour of oxides with water (3.1j) and the acidities of chlorine-substituted ethanoic acids (10.6c)

    Please explain me the last chlorine substituted ethanoic acid part someone
Click to expand...

The concept of electronegativity, bond polarity and diapoles are related to AS....its in (shapes and bonding ch..CH4) , the behaviour of oxides with water is the topic of AS inorganic and the and the acidities of chlorine-substituted ethanoic acids falls under A2 organic...

chlorine substituted ethanoic acid are mono chloroethonic acid and di or tri chloroethanoic acid .... C-Cl3-CooH , Cl-CH2-Cooh etc etc .....under this topic u have to explain the effect of chlorine on the strength of acids.... just have a look on m/j 12 (42) ..there's a question about it ...if you'll see that maybe then you'll have a better idea of that .
 
chocolate_girl

chocolate_girl

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Hassan Ali Abid said:
The concept of electronegativity, bond polarity and diapoles are related to AS....its in (shapes and bonding ch..CH4) , the behaviour of oxides with water is the topic of AS inorganic and the and the acidities of chlorine-substituted ethanoic acids falls under A2 organic...

chlorine substituted ethanoic acid are mono chloroethonic acid and di or tri chloroethanoic acid .... C-Cl3-CooH , Cl-CH2-Cooh etc etc .....under this topic u have to explain the effect of chlorine on the strength of acids.... just have a look on m/j 12 (42) ..there's a question about it ...if you'll see that maybe then you'll have a better idea of that .
Click to expand...

Emm im an AS level student and i also thought that this part isnt in the syllabus but the cie official syllabus says it is although i hvnt met anysuch questions in past papers so far

Can u please tell me if any of these syllabus contents are included in the AS level

1)describe the formation of carboxylic acids from nitriles
2)describe the reactions of carboxylic acids in the formation of acyl chloride
3)describe the formation of amides from the reaction between RNH2 and R'COCl
4)describe amide hydrolysis on treatment with aqueous alkali or acid
 
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sitooon

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what does this point mean in Ms " line is a continuous curve of best fit that does not deviate to accommodate an off curve point. " ?
 
Hassan Ali Abid

Hassan Ali Abid

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chocolate_girl said:
Emm im an AS level student and i also thought that this part isnt in the syllabus but the cie official syllabus says it is although i hvnt met anysuch questions in past papers so far

Can u please tell me if any of these syllabus contents are included in the AS level

1)describe the formation of carboxylic acids from nitriles
2)describe the reactions of carboxylic acids in the formation of acyl chloride
3)describe the formation of amides from the reaction between RNH2 and R'COCl
4)describe amide hydrolysis on treatment with aqueous alkali or acid
Click to expand...


1. Yes its in the AS topic ... Acid hydrolysis of nitriles produces carboxylic acid ...do learn its conditions and reagents.
2. Its an an topic ...u dont need to know about it
3 and 4. They falls under A2 organic.

* You should know about the reduction of nitriles (This equ is of both AS and A2..).
 
daredevil

daredevil

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sitooon said:
what does this point mean in Ms " line is a continuous curve of best fit that does not deviate to accommodate an off curve point. " ?
Click to expand...
basically that u have to make a straight best fit line... leaving out the points that don't fal on the line
 
Hassan Ali Abid

Hassan Ali Abid

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daredevil said:
i got confused by this...


see iii ^
Click to expand...

They had confused the students by drawing the skeletal formula and then asking to draw the monomers...and i guess u just stuck with that skeletal formula given in the question ..ryt ?

for that u can simply change the compound given in the question in to structural formula ...and try to open the structures ...and then proceed to see what they have asked in the question.

In that in is quite visible that polymer is made up of two monomers .....and each monomer is having the same functional groups its each side ....so one is di-Phenol and one is HO-C5H10-OH ...instead of OH u can also write Cl.
Did u get it ?? :unsure::unsure:
 
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sitooon

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daredevil said:
basically that u have to make a straight best fit line... leaving out the points that don't fal on the line
Click to expand...
It says " curve " , how straight line ? and the curve should pass through all points but thats not what the marking scheme are looking for
 
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