1. Which one of the following is the correct statement?

A. Boric acid is a protonic acid
B. Beryllium exhibits coordination number of six
C. Chlorides of both beryllium and aluminium have bridged chloride structures in solid phase
D. $${B_2}{H_6}2N{H_3}$$   is known as ‘inorganic benzene’
Answer :   Chlorides of both beryllium and aluminium have bridged chloride structures in solid phase
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2. Which of the following are peroxoacids of sulphur?

A. $${H_2}S{O_5}\,\,{\text{and}}\,\,{H_2}{S_2}{O_8}$$
B. $${H_2}S{O_5}\,\,{\text{and}}\,\,{H_2}{S_2}{O_7}$$
C. $${H_2}{S_2}{O_7}\,\,{\text{and}}\,\,{H_2}{S_2}{O_8}$$
D. $${H_2}{S_2}{O_6}\,\,{\text{and}}\,\,{H_2}{S_2}{O_7}$$
Answer :   $${H_2}S{O_5}\,\,{\text{and}}\,\,{H_2}{S_2}{O_8}$$
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3. Which of the following bonds will be most polar?

A. $$N—Cl$$
B. $$O—F$$
C. $$N—F$$
D. $$N—N$$
Answer :   $$N—F$$
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4. Bauxite ore is generally contaminated with impurity of oxides of two elements $$X$$ and $$Y.$$ Which of the following statement is correct ?

A. $$X$$ is a non-metal and belongs to the third period while $$Y$$ is a metal and belongs to the fourth period.
B. One of two oxides has three-dimensional polymeric structure.
C. Both (A) and (B) are correct.
D. None of the above.
Answer :   Both (A) and (B) are correct.
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5. $$AlC{l_3}$$  achieves stability by forming a dimer. In trivalent state the compound is hydrolysed in water. $$AlC{l_3}$$  in acidified aqueous solution forms

A. $$Al{\left( {OH} \right)_3} + HCl$$
B. $${\left[ {Al{{\left( {{H_2}O} \right)}_6}} \right]^{3 + }} + 3C{l^ - }$$
C. $$AlC{l_3} \cdot 2{H_2}O$$
D. $$A{l_2}{O_3} + HCl$$
Answer :   $${\left[ {Al{{\left( {{H_2}O} \right)}_6}} \right]^{3 + }} + 3C{l^ - }$$
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6. In the reaction
$$HN{O_3} + HF \to {H_2}\mathop N\limits^ + {O_3} + {F^ - }$$       base is

A. $$HF$$
B. $$HN{O_3}$$
C. $$HF\,\,{\text{and}}\,\,HN{O_3}$$
D. $${\text{None of these}}$$
Answer :   $$HN{O_3}$$
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7. The brown ring test for $$NO_2^ - $$  and $$NO_3^ - $$  is due to the formation of complex ion with a formula

A. $${\left[ {Fe{{\left( {{H_2}O} \right)}_6}} \right]^{2 + }}$$
B. $${\left[ {Fe\left( {NO} \right){{\left( {CN} \right)}_5}} \right]^{2 + }}$$
C. $${\left[ {Fe{{\left( {{H_2}O} \right)}_5}NO} \right]^{2 + }}$$
D. $${\left[ {Fe\left( {{H_2}O} \right){{\left( {NO} \right)}_5}} \right]^{2 + }}$$
Answer :   $${\left[ {Fe{{\left( {{H_2}O} \right)}_5}NO} \right]^{2 + }}$$
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8. From the following information
$$X + {H_2}S{O_4} \to Y$$     ( a colourless and irritating gas )
$$Y + {K_2}C{r_2}{O_7} + {H_2}S{O_4} \to $$      ( green coloured solution )
Identify the pair $$X$$  and $$Y.$$

A. $$\bar Cr,HCl$$
B. $$SO_3^{2 - },S{O_2}$$
C. $${S^{2 - }},{H_2}S$$
D. $$CO_3^{2 - },C{O_2}$$
Answer :   $$SO_3^{2 - },S{O_2}$$
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9. The structure of diborane $$\left( {{B_2}{H_6}} \right)$$  contains

A. four $$2c - 2e$$  bonds and four $$3c - 2e$$  bonds
B. two $$2c - 2e$$  bonds and two $$3c - 3e$$  bonds
C. two $$2c - 2e$$  bonds and four $$3c - 2e$$  bonds
D. four $$2c - 2e$$  bonds and two $$3c - 2e$$  bonds
Answer :   four $$2c - 2e$$  bonds and two $$3c - 2e$$  bonds
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10. What is the correct observation when $$B{r_2}$$  is treated with $$NaF, NaCl$$   and $$NaI$$  taken in three test-tubes labelled as $$(X), (Y)$$  and $$(Z)?$$
P - Block Elements mcq question image

A. $${F_2}$$  is liberated in $$(X)$$  and $$C{l_2}$$  in $$(Y).$$
B. Only $${I_2}$$  is liberated in $$(Z).$$
C. Only $$C{l_2}$$  is liberated in $$(Y).$$
D. Only $${F_2}$$  is liberated in $$(X).$$
Answer :   Only $${I_2}$$  is liberated in $$(Z).$$
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