NEET Chemistry Concepts of Acids & Bases NEET PYQ-Concepts Of Acids Bases

  • question_answer
    In which of the following arrangements the given sequence is not strictly according to the property indicated against it?         [AIPMT (M) 2012]

    A)  \[HF<HCl<HBr,HI:\] increasing acidic strength

    B) \[{{H}_{2}}O<{{H}_{2}}S<{{H}_{2}}Se<{{H}_{2}}Te:\] increasing \[p{{K}_{a}}\] values

    C)  \[N{{H}_{3}}<p{{H}_{3}}<As{{H}_{3}}<Sb{{H}_{3}}:\] increasing acidic character

    D)  \[C{{O}_{2}}<Si{{O}_{2}}<Sn{{O}_{2}}<Pb{{O}_{2}}\]: increasing oxidising power

    Correct Answer: B

    Solution :

    (a,c) As we move from top to bottom in a group, acidic strength of hydrides increases. Therefore, order of acidic strength of hydrides of V A and group elements is
    \[N{{H}_{3}}<P{{H}_{3}}<As{{H}_{3}}<Sb{{H}_{3}}\]
    \[HF<HCl<HBr<HI\]
     As we move from top to bottom in a group, acidic nature \[({{K}_{a}})\]increases. Therefore, \[p{{K}_{a}}\] decreases. Thus order of \[p{{K}_{a}}\] values of hydrides of VI A group elements is
    \[{{H}_{2}}O>{{H}_{2}}S>{{H}_{2}}Se>{{H}_{2}}Te\]
    [d] On moving form top to bottom, oxidising power of oxides increases. Thus order of oxidising power of oxides of IVA group elements is
    \[C{{O}_{2}}<Si{{O}_{2}}<Sn{{O}_{2}}<Pb{{O}_{2}}\]


You need to login to perform this action.
You will be redirected in 3 sec spinner