Order of boiling point is :
HF > HI > HBr > HCl
HF > HBr > HI > HCl
HCl > HBr > HI > HF
HCl > HI > HBr > HF
A.
HF > HI > HBr > HCl
Boiling point of hydrogen halides increase with increasing molecular mass because van der Waals' force of attraction increase with rise in molecular weight .Hydrogen fluoride (HF) has abnormally high boiling point due to their existence as a polymeric compound by forming inter-molecular hydr-ogen bonding .
Thus decreasing order of boiling point is
> HI > HBr >
Assertion : Chloral reacts with phenyl chloride to form DDT.
Reason : It is an electrophilic substitution reaction.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion : Mixture of CH3COOH and CH3COONH4 is an example of acidic buffer.
Reason : Acidic buffer contains equimolar mixture of weak acid and its salt with weak base.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
Assertion : Alkyl iodide can be prepared by treating alkyl chloride/bromide with NaI in acetone.
Reason : NaCl/NaBr are soluble in acetone while NaI is not.
If both assertion and reason are true and reason is the correct explanation of assertion.
If both assertion and reason are true but reason is not the correct explanation of assertion.
If assertion is true but reason is false.
If both assertion and reason are false.
SN2 mechanism is involed in the following substitution :
CH3-CH2-Cl + OH-
(CH3)2-C(Cl)-CH3-OH-
(CH3)2-C-Cl + OH-
CH3-CH2-(CH3)C(Cl)-CH3 + OH-
Arrange the hydra - acids of halogens in increasing order of acidity .
HF < HCl < HBr < HI
HI < HBr < HCl < HF
HF < HBr < HI <HCl
HF < HI < HBr < HCl