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Chemistry: Post your doubts here!

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Please can anybody help me with these question . I cant able to understand them. Question 20 in first screenshot and question 10 in the second one .thanks
In q20 you have to look for the longest chain. And in this qs longest chain contains 5 carbons. Start numbering from the carbon closest to the functional group so ans is C
 
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In q20 you have to look for the longest chain. And in this qs longest chain contains 5 carbons. Start numbering from the carbon closest to the functional group so ans is C
So its like a rule that we start measuring of carbon which is closest to the fuctional group. Thanks .
 
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for Q 10 B and D are wrong as there is no change in oxidation state,C cant be correct as an acid must have H+ ions so A is the answer
In question 10 I know the answer B,C,D are wrong but i cant seem to understand how is A answer. Hso3- doesnt look like it is acting as a base. Correct me if i am wrong.
 
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Guys do we have to wash the conical flask before performing the next titration or nah?

If it is unused, there is no need to wash it.

If used, definitely wash it with distilled water. Unlike what some students think, there is no need to dry the flasks though.
 
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1. Cl2 + Mg ---> MgCl2 and 1/2 Cl2 + Na ---> NaCl
Chlorine reacts with Mg to form MgCl2 bu reacts with Na to form NaCl. So twice the number of moles of Cl react with Mg (X) compared to Na (Y). This option is correct.

2. Again, Cl2 reacts with H2 to form 2HCl: Cl2 + H2 ---> 2HCl
and Chlorine displaces Br in KBr: 1/2 Cl + KBr ---> KCl + HBr
So twice the no of moles of Cl2 react with H2 compared to Kbr. So this option is also correct

3. Cl2 + 2NaOH ---> NaCl +NaCLO + H2O
3Cl2 +6 NaOH ---> 5NaCl + NaClO3 + 3H2O
In both of these reactions, Cl2 and NaOH react in the ratio 1:2. So the number of moles of Cl2 that react with 1 mol of X isn't twice the number of moles that react with Y. So this option is wrong. The ans is B
 
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1. Cl2 + Mg ---> MgCl2 and 1/2 Cl2 + Na ---> NaCl
Chlorine reacts with Mg to form MgCl2 bu reacts with Na to form NaCl. So twice the number of moles of Cl react with Mg (X) compared to Na (Y). This option is correct.

2. Again, Cl2 reacts with H2 to form 2HCl: Cl2 + H2 ---> 2HCl
and Chlorine displaces Br in KBr: 1/2 Cl + KBr ---> KCl + HBr
So twice the no of moles of Cl2 react with H2 compared to Kbr. So this option is also correct

3. Cl2 + 2NaOH ---> NaCl +NaCLO + H2O
3Cl2 +6 NaOH ---> 5NaCl + NaClO3 + 3H2O
In both of these reactions, Cl2 and NaOH react in the ratio 1:2. So the number of moles of Cl2 that react with 1 mol of X isn't twice the number of moles that react with Y. So this option is wrong. The ans is B
Thankyou got it
 
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a problem:
The compound pentan-1,4-diol has two OH groups per molecule and can be oxidised.
Which statements about pentan-1,4-diol or its oxidation products are correct?
1. When one mole of pentan-1,4-diol reacts with an excess of sodium metal, one mole of hydrogen molecules is produced.
2. At least one of the possible oxidation products of pentan-1,4-diol will react with 2,4-dinitrophenylhydrazine reagent.
3. Dehydration of pentan-1,4-diol could produce a compound with empirical formula C5H8.

which statement(s) is/are correct?
may/june 2014, variant 11 question 39.
 
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