Multiple choice question

In any group atomic mass increase gives a change in properties which property
is increased and which one is decreased? The elements in which ns 2 electrons
are not much active which type of effect is reflected? How this effect is
noted on their physical and chemical properties?
iz'u&17 13 os lewg ds rRoksa dks B-CykWd ds rRo D;ksa dgk tkrk gS\ budh lkekU;r%
iznf'kZr dh tkus okyh la;kstdrk bySDVªkWfud foU;kl ds vk/kkj ij fdruh
gksuh pkfg;s\ {kkjh; /kkrq ,oa {kkjh; e`nk /kkrqvksa dh rqyuk esa blds fdl xq.k
esa o`f) gksrh gS\
Why group–13 elements have been named as B-block elements? On the ground
of their electronic configuration, how much valency they should represent
which property is increased as compared to alkali and alkaline earth metals?
iz'u&18 cksjsDl dk jklk;fud lw= ,oa izkfIr LFkku fy[kks\ cksjkWu VªkbZ gSykbM dks
ywbl vEy D;ksa dgk tkrk gS\ NH ls bl vEy dh fØ;k n'kkZb;s\
3
Give chemical formula for Borex? Why Boron tri–halide is called Lewis
acid? Give reaction of this acid with NH 3 ?
iz'u&19 cksfjd ,u gkbMªkbM vkFkksZcksfjd vEy rFkk esVkcksfjd vEy ,oa VsVªkcksfjd
vkSj ik;jkscksfjd vEy ds jklk;fud lw= nhft;s\ vkFkksZ cksfjd vEy ls eSVk
cksfjd] VsVªk cksfjd vEy vkSj cksfjd ,ugkbMªkbM cukus dh ifjfLFkfr;ksa dk
lehdj.k lfgr mYys[k dhft;s\
Give chemical formulas for boric anhydried, ortho boric acid meta boric
acid, tetra boric acid and pyro boric acids? How will you get meta boric acid,
tetra boric acid and boric anhydried from ortho boric acid. Give chemical
equation and necessary conditions for it?
iz'u&20 dSfY'k;e cksjsV (Ca B O ) ij lksfM;e dkcksZusV (Na CO ) ds e/; gksus okyh
2 6 11 2 3
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vEy dh lajpuk nhft;s\
71