301. In solid state $$PC{l_5}$$ is a ________.
A
covalent solid
B
octahedral structure
C
ionic solid with $${\left[ {PC{l_6}} \right]^ + }$$ octahedral and $${\left[ {PC{l_4}} \right]^ - }$$ tetrahedral
D
ionic solid with $${\left[ {PC{l_4}} \right]^ + }$$ tetrahedral and $${\left[ {PC{l_6}} \right]^ - }$$ octahedral
Answer :
ionic solid with $${\left[ {PC{l_4}} \right]^ + }$$ tetrahedral and $${\left[ {PC{l_6}} \right]^ - }$$ octahedral
302. $$A{l_2}{O_3}$$ can be converted into anhydrous $$AlC{l_3}$$ by heating
A
$$A{l_2}{O_3}$$ with $$HCl$$ gas
B
$$A{l_2}{O_3}$$ with $$NaCl$$ in solid state
C
a mixture of $$A{l_2}{O_3}$$ and carbon in dry $$C{l_2}$$ gas
D
$$A{l_2}{O_3}$$ with $$C{l_2}$$ gas.
Answer :
a mixture of $$A{l_2}{O_3}$$ and carbon in dry $$C{l_2}$$ gas
303. $${P_2}{O_5}$$ is heated with water to give
A
hypophosphorous acid
B
phosphorous acid
C
hypophosphoric acid
D
orthophosphoric acid
Answer :
orthophosphoric acid
304. To a piece of charcoal, sulphuric acid is added. Then :
A
there is no reaction
B
water gas is formed
C
$$S{O_2}$$ and $$C{O_2}$$ are evolved
D
$$CO$$ and $$S{O_2}$$ are evolved
Answer :
$$S{O_2}$$ and $$C{O_2}$$ are evolved
305. Heating an aqueous solution of aluminium chloride to dryness will give
A
$$Al\left( {OH} \right)C{l_2}$$
B
$$A{l_2}{O_3}\,$$
C
$$A{l_2}C{l_6}$$
D
$$AlC{l_3}$$
Answer :
$$A{l_2}{O_3}\,$$
306. When sugar is treated with $$conc.$$ sulphuric acid, the sugar is charred. In this process, sugar is
A
reduced
B
oxidized
C
sulphonated
D
dehydrated
Answer :
dehydrated
307. Which one of the following statement regarding helium is incorrect?
A
It is used to produce and sustain powerful
superconducting magnets
B
It is used as a cryogenic agent for carrying out
experiments at low temperatures
C
It is used to fill gas balloons instead of hydrogen
because it is lighter and non-inflammable
D
It is used in gas-cooled nuclear reactors
Answer :
It is used to fill gas balloons instead of hydrogen
because it is lighter and non-inflammable
308.
Among the following molecules,
$$\eqalign{
& \left( {\text{i}} \right)Xe{O_3} \cr
& \left( {{\text{ii}}} \right)XeO{F_4} \cr
& \left( {{\text{iii}}} \right)Xe{F_6} \cr} $$
those having same number of lone pairs on $$Xe$$ are
A
(i) and (ii) only
B
(i) and (iii) only
C
(ii) and (iii) only
D
(i), (ii) and (iii)
Answer :
(i), (ii) and (iii)
309. Which of the following statements is wrong?
A
Single $$N-N$$ bond is stronger than the single $$P-P$$ bond.
B
$$P{H_3}$$ can act as a ligand in the formation of coordination compound with transition elements.
C
$$N{O_2}$$ is paramagnetic in nature.
D
Covalency of nitrogen in $${N_2}{O_5}$$ is four.
Answer :
Single $$N-N$$ bond is stronger than the single $$P-P$$ bond.
310. Which of the following statements is not correct?
A
Helium has the lowest boiling point among the noble gases.
B
Argon is used in electric bulbs.
C
Krypton is obtained during radioactive disintegration.
D
$$Xe$$ forms $$Xe{F_6}.$$
Answer :
Krypton is obtained during radioactive disintegration.