52671 + Interview Questions in Chemistry in Class 11

1.	The oxides of alkali and alkali earth metals are basic and the their strenght increases down the group. The solubility of carbonates and sulphates of alkali and earth metals shown opposite trends. Only the carbonates of Li and alkaline earth metals decompose on heating. The bicarbonates of both alkali and alkali earth metals on heating give carbonates indentify the correct order of thermal stablities
Answer» `K_(2)OltMgCO_(3)ltCaCO_(3)gtBeCO_(3)` `BeCO_(3)ltCaCO_(3)ltMgCO_(3)ltK_(2)CO_(3)` `BeCO_(3)ltMgCO_(3)ltCaCO_(3)ltK_(2)CO_(3)` `CaCO_(3)ltBeCO_(3)ltMgCO_(3)ltK_(2)CO_(3)` SOLUTION :The thermal stability of cabonates of IIA GROUP elements increases from Be to Ba. Which can be EXPLAINED on the basis of stability of oxide formed when they decomposed

Discussion

2.	The oxides of alkali and alkali earth metals are basic and the their strenght increases down the group. The solubility of carbonates and sulphates of alkali and earth metals shown opposite trends. Only the carbonates of Li and alkaline earth metals decompose on heating. The bicarbonates of both alkali and alkali earth metals on heating give carbonatesThe correct decreasing order of basic character of the oxides is
Answer» `K_(2)OgtMgOgtSrOgtCs_(2)O` `Cs_(2)OgtK_(2)OgtSrOgtMgO` `MgOgtSrOgtK_(2)OgtCs_(2)O` `Cs_(2)OgtK_(2)OgtMgOgtSrO` Solution :As electropositive character of METAL in metal OXIDE INCREASES basic character increases

Discussion

3.	The oxide(s) formed upon combustion of sodium metal in excess air is/are
Answer» `Na_(2)O_(2)` `Na_(2)O` `NaO_(2)` NaOH Solution :`4Na+O_(2)rarr2Na_(2)O` `2Na+2O_(2)rarr2Na_(2)O_(2)`

Discussion

4.	The oxide Tl_n Ca_2 Ba_2 Cu_3 O_10 is found to be superconductor at 125 K. The value of n is
Answer» Solution :As given MOLECULE is neutral , sum of oxidation states =0 . HENCE,n(+3)+2(+2)+2(+2)+3(+2)+10(-2)=0 or 3N +4 +4 +6-20=0 or 3 n =6 or n=2

Discussion

5.	The oxide TI_(n) , Ca_(2), Ba_(2) Cu_(u) O_(14) is found to be superconductor at 125 K. the value of n is
Answer» Solution :As given molecule is neutral, sum of oxidation STATE = 0 . HENCE N (+3) + 2 ( +2) + 2 ( +2) + 3 ( +2)+ 10 ( -2) =0 or 3 n + 4 + 4 + 6 -20 = 0 or 3 n = 6 or n =2

Discussion

6.	The oxide that gives H_2O_2 on treatment with dilute H_2SO_4 is
Answer» `PbO_2` `BaO_2 . 8H_2O + O_2` `MnO_2` `TiO_2` SOLUTION :OXIDES such as `BaO_2,Na_2O_2` etc. which contain peroxide linkage (i.e., -O-O- or `O_2^(2-)` ) on treatment with dilute `H_2SO_4` give `H_2O_2` but oxides (O = M = O, where M is the METAL ATOM) such as `PbO_2, MnO_2, TiO_2`, do not give `H_2O_2` on treatment with dilute `H_2SO_4`. `BaO_2. 8H_2O_((s)) + H_2SO_(4(aq)) to BaSO_(4(s)) + H_2O_(2(aq)) + 8H_2O_((l))`

Discussion

7.	The oxide that gives H_(2)O_(2) on treatment with dilute H_(2)SO_(4) is …………….
Answer» `PbO_(2)` `BaO_(2).8H_(2)O` `MnO_(2)` `TiO_(2)` Solution :Oxides such as `BrO_(2), Na_(2)O_(2)`, etc. which contain peroxide LINKAGE (i.e., `""_(-)O-O^(-)` or `O_(2)^(2-)`) on treatmentwith DIL. `H_(2)SO_(4)` give `H_(2)O_(2)` but dioxides (O=M=O, where M is the metalatom) such as `PbO_(2), MnO_(2), TiO_(2)` do not give `H_(2)O_(2)` on treatment with dil. `H_(2)SO_(4)` .

Discussion

8.	The oxide of an element contains 67.67% of oxygen. Equivalent weight of the element is
Answer» `2.46` `3.82` `4.36` `4.96` Solution :`67.67=(16n)/(M)XX100" "("for"X_(2)O_(N))` `32.33=(2X)/(M)xx100` `impliesE=(X)/(n)=(32.33xx16)/(67.67xx2)=3.82`

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9.	The oxide of a metal contains 40% of oxygen. The valency of metal is 2. What is the atomic weight of metal?
Answer» 24 12 40 36 Answer :A

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10.	The oxidation unmber of two S stoms in Na_(2)S_(2)O_(3) are ………….and …………….
Answer» ANSWER :`-2 and +6`

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11.	The oxidation states of V and Br in V (BrO_2)_2 are respectively
Answer» 2 and 2 2 and 1 4 and 2 2 and 3 ANSWER :D

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12.	The oxidation states of the most elecrtronegative element in the products of rection between BaO^(2) and diluent H_(2)SO_(4) are:
Answer» `-1` `+1` `-2` 0 Solution :`BaO_(2)+H_(2)SO_(4)+H_(2)SO_(4)rarrBaSO_(4)+H_(2)O_(2)` Oxidation state of O in `BaSO_(4)`=-2"and in"H_(2)O_(2)`=-1`

Discussion

13.	The oxidation states of the most electronegative element in the products of the reaction, BaO_2 with dil. H_2SO_4 are……
Answer» 0 and -1 `-1` and -2 `-2` and 0 `-2` and +1 Answer :B

Discussion

14.	The oxidation states of S atoms in S_(4)O_(6)^(2-) from left to righ respectively are .^(-)O-overset(O)overset("\|\|")underset(O)underset("\|\|")(S)-S-S-overset(O)overset("\|\|")underset(O)underset("\|\|")(S)-O^(-)
Answer» `+6,0,0,+6` `+3,+1,+1,+3` `+5,0,0,+5` `+4,+1,+1,+4` ANSWER :C

Discussion

15.	The oxidation states of iodin in HIO_(4),H_(3)IO_(5) and H_(5)IO_(6) are respectively
Answer» `+1,+3,+7` `+7+7+3` `+7+7+7` `+7+5+3` SOLUTION :`HIO_(4),H_(3)IO_(5),H_(5)OI_(6)`

Discussion

16.	The oxidation sates of iodine in HIO_(4), H_(3)IO_(5) and H_(5)IO_(6) are respectively :
Answer» `+1,+3,+7` `+7,+7,+3` `+7,+7,+7` `+7,+5,+3` ANSWER :C

Discussion

17.	The oxidation states exhibited by hydrogen in its various compounds are
Answer» `-1` only ZERO only `+1,-1` and zero `+1 ` only Answer :C

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18.	The oxidation states exhibited by hydrogen in its various compounds are....
Answer» `-1` only ZERO only `+1,-1` and zero `+1` only ANSWER :C

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19.	The oxidation state of underlined in compound Ba_(2)XeO_(2)
Answer» 0 `+8` `+6` 5 Answer :A

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20.	The oxidation states of the most electronegative element in the products of the reaction between BaO_(2) with dilute H_(2) SO_(4) are
Answer» 0 and- 1 `-1 and -2` `-2 and 0` `-2 and +2` Solution :Fluorine ALWAYS exhibits ... COMPOUNDS

Discussion

21.	What is the oxidation number of sulphur in Na_(2)S_(4)O_(6)?
Answer» `3//2` `2//3` `5//2` `2//5` SOLUTION :`S_(4)O_(6)^(-2)4x+6(-2)=-2,4x=10,x=10/4=5/2` `Naoverset(Theta)O-overset(O)overset(\|\|)UNDERSET(O)underset(\|\|)(S^(+5))-S^(0)-S^(0)-overset(O)overset(\|\|)underset(O)underset(\|\|)(S^(+5))-overset(Theta)ONa`

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22.	The oxidation state of sulphur in Na_(2)S_(4)O is
Answer» `3//2` `2//3` `5//2` `2//5` ANSWER :C

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23.	The oxidation state of sulphur in Caro.s and Marshel.s acids are:
Answer» `S^(6+), 5^(6+)` `S^(6+), S^(7+)` ` S^(6+), S^(5+)` ` S^(6+), S^(6-)` Solution :`H_2SO_5` (Caro.s acid) `overset(-1)(HO)-overset(-2)overset(O)overset(\|\|)underset(-2)underset(O)underset(\|\|)S-overset(1)o-overset(-1)O-overset(+1)H""+6` `H_2S_2O_8` (Marshaall.s acid) `HO-overset(O)overset(\|\|)underset(O)underset(\|\|)S-O-O-overset(O)overset(\|\|)underset(O)underset(\|\|)S-OH""+6`

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24.	The oxidation state of S in S_(8) is zero.
Answer» ANSWER :T

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25.	The oxidation state of S in Caro's acid ( permono sulphuric acid ) H_(2)SO_(5) is "_____________".
Answer» `+8` `+6` `+5` `+4` ANSWER :B

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26.	The oxidation state of phosphours is minimum in
Answer» <P>`P_(4)O_(6)` `NaH_(2)PO_(2)` `PH_(3)` `Na_(3)PO_(4)` Solution :`overset(-3)(P)H_(3)`

Discussion

27.	The oxidation state of phosphorus is minimum in
Answer» `P_(4)O_(6)` `NaH_(2)PO_(2)` `PH_(3)` `Na_(3)PO_(4)` ANSWER :C

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28.	The oxidation state of phosphorus in Ba(H_2PO_2)_2 is
Answer» `+3` `+2` `+1` `-1` ANSWER :C

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29.	The oxidation state of phosphorus in cyclotrimetaphosphoric acid is
Answer» `+3` `+5` `-3` `+2` SOLUTION :O.S. of P in `(HPO_(3))_(3)" is "(+1+x-6)_(3)=0orx=+5`

Discussion

30.	The oxidation statel of oxygen in superoxide is
Answer» `-1` `-2` `-(1)/(2)` `+1` ANSWER :C

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31.	The oxidation state of Mo in Mo_(2)Cl_(8) ^(4-) ion is "_____________".
Answer» `-4` `-2` `+6` `+2` ANSWER :C

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32.	The oxidation state of Mn in B is :
Answer» 0 `+2` `+4` `+6` Answer :C

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33.	The oxidation state of I in H_(4)IO_(6)^(-) , is
Answer» `+7` `-1` `+5` `+1` SOLUTION :`H_(4)IO_(6)^(-) ,I=+5`

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34.	The oxidation state of iodine in H_(4)IO_(6)^(-) is:
Answer» `+7` `+5` `+1` `-1` ANSWER :A

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35.	The oxidation state of hydrogen in CaH_(2) is +1.
Answer» ANSWER :F

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36.	The oxidation state of Cr in [Cr(NH_(3))_(4)Cl_(2)]^(+) is
Answer» 0 `+1` `+2` `+3` ANSWER :D

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37.	The oxidation state of Cr in Cr(CO)_6 is
Answer» 0 `+2` `-2` `+6` ANSWER :A

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38.	The oxidation state of chromium in the final product formed by the reaction betweenKI and acidified potassium dichromate solution is
Answer» `+3` `+2` `+6` `+4` Solution :`K_(2)Cr_(2)O_(7)//H_(2)SO_(4)` oxidises KI to `I_(2)` and itself REDUCED to `Cr_(2)(SO_(4)^(3))` `K_(2)Cr_(2)O_(7)RARROVERSET(+3)Cr_(2)(SO_(4)^(3))`

Discussion

39.	The oxidation state of chromium in the final product formed by the reaction between Kl and acidified potassium dichromate solution is
Answer» `+3` `+2` `+6` `+4` ANSWER :A

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40.	The oxidation state of chromium in [Cr(PPh_(3))_(3)(CO)_(3)] is
Answer» `+3` `+8` zero `+5` ANSWER :C

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41.	The oxidation state of chromium in Cr(CO)_(6) is ____
Answer» 0 `+2` `-2` `+6` ANSWER :A

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42.	The oxidation state of central atom in the anion of compound NaH_(2)PO_(2) will be ……… .
Answer» `+3` `+5` `+1` `-3` Solution :`OVERSET(+1)(Na)overset(+1)((H)_(2))overset(X)Poverset(-2)O` Here, `(+1)+2(+1)+x+2(-2)=0,i.e.,x=+1`.

Discussion

43.	The oxidation state of Barium in Ba(H_(2)PO_(2))_(2) is
Answer» `+3` `+2` `+1` `-1` ANSWER :B

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44.	The oxidation state of a substance increases in oxidation and decreases in reduction.
Answer» ANSWER :T

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45.	The oxidation state of a substance in its elementary state is equal to
Answer»

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46.	The oxidation sate of +3 for phosphorus is in
Answer» hypophosphorous ACID meta-phosphoric acid ortho-phosphoric acid PHOSPHOROUS acid SOLUTION :`H_3overset(+3)(PO_3)`Phosphorous acid `H_3overset(+5)(PO_4)`Ortho phosphoric acid `Hoverset(+5)(PO_3)`METAPHOSPHORIC acid `H_3overset(+1)(PO_2)` Hypo phosphorous acid

Discussion

47.	The oxidation product of ethylene by air at 200-400^(@)C in presence of silver catalyst is
Answer» ETHYLENE GLYCOL Ethylene OXIDE 1,2-Ethanediol Ethylene chlorohydrin ANSWER :B

Discussion

48.	The oxidation potential of A and B are + 2.37 and+ 1.66 V respectively.In a chemical reaction
Answer» A will be REPLACED by B A will repalce B A will not replace B A and B will not replace each other SOLUTION :A will replace B as A LIES above B in the acitivity series

Discussion

49.	The oxidation of benzene by V_(2)O_(5) in the presence of air produce :
Answer» BENZOIC acid benzaldehyde benzoic anhydride maleic anhydride Solution :

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50.	The oxidation of an alcohol (C_(5)H_(12)O) with acid dichromate gives a mixture of dimethyl ketone and acetic acid. The alcohol is
Answer» 2-dimethyl-3-butanol 2-methyl-1-butanol 2-methyl-2-butanol 3-methyl-2-butanol Solution :This alcohol `C_(5)H_(12)O` gives a KETONE with lesser number of CARBON ATOMS. This has to be `3^(@)` alcohol. This is possible in the following structure only : `underset("2-Methyl-2-butanol")(CH_(3)-underset(CH_(3))underset(\|)OVERSET(OH)overset(\|)(C)-CH_(2)CH_(3))`

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

The oxide(s) formed upon combustion of sodium metal in excess air is/are

The oxide Tl_n Ca_2 Ba_2 Cu_3 O_10 is found to be superconductor at 125 K. The value of n is

The oxide TI_(n) , Ca_(2), Ba_(2) Cu_(u) O_(14) is found to be superconductor at 125 K. the value of n is

The oxide that gives H_2O_2 on treatment with dilute H_2SO_4 is

The oxide that gives H_(2)O_(2) on treatment with dilute H_(2)SO_(4) is …………….

The oxide of an element contains 67.67% of oxygen. Equivalent weight of the element is

The oxide of a metal contains 40% of oxygen. The valency of metal is 2. What is the atomic weight of metal?

The oxidation unmber of two S stoms in Na_(2)S_(2)O_(3) are ………….and …………….

The oxidation states of V and Br in V (BrO_2)_2 are respectively

The oxidation states of the most elecrtronegative element in the products of rection between BaO^(2) and diluent H_(2)SO_(4) are:

The oxidation states of the most electronegative element in the products of the reaction, BaO_2 with dil. H_2SO_4 are……

The oxidation states of S atoms in S_(4)O_(6)^(2-) from left to righ respectively are .^(-)O-overset(O)overset("||")underset(O)underset("||")(S)-S-S-overset(O)overset("||")underset(O)underset("||")(S)-O^(-)

The oxidation states of iodin in HIO_(4),H_(3)IO_(5) and H_(5)IO_(6) are respectively

The oxidation sates of iodine in HIO_(4), H_(3)IO_(5) and H_(5)IO_(6) are respectively :

The oxidation states exhibited by hydrogen in its various compounds are

The oxidation states exhibited by hydrogen in its various compounds are....

The oxidation state of underlined in compound Ba_(2)XeO_(2)

The oxidation states of the most electronegative element in the products of the reaction between BaO_(2) with dilute H_(2) SO_(4) are

What is the oxidation number of sulphur in Na_(2)S_(4)O_(6)?

The oxidation state of sulphur in Na_(2)S_(4)O is

The oxidation state of sulphur in Caro.s and Marshel.s acids are:

The oxidation state of S in S_(8) is zero.

The oxidation state of S in Caro's acid ( permono sulphuric acid ) H_(2)SO_(5) is "_____________".

The oxidation state of phosphours is minimum in

The oxidation state of phosphorus is minimum in

The oxidation state of phosphorus in Ba(H_2PO_2)_2 is

The oxidation state of phosphorus in cyclotrimetaphosphoric acid is

The oxidation statel of oxygen in superoxide is

The oxidation state of Mo in Mo_(2)Cl_(8) ^(4-) ion is "_____________".

The oxidation state of Mn in B is :

The oxidation state of I in H_(4)IO_(6)^(-) , is

The oxidation state of iodine in H_(4)IO_(6)^(-) is:

The oxidation state of hydrogen in CaH_(2) is +1.

The oxidation state of Cr in [Cr(NH_(3))_(4)Cl_(2)]^(+) is

The oxidation state of Cr in Cr(CO)_6 is

The oxidation state of chromium in the final product formed by the reaction betweenKI and acidified potassium dichromate solution is

The oxidation state of chromium in the final product formed by the reaction between Kl and acidified potassium dichromate solution is

The oxidation state of chromium in [Cr(PPh_(3))_(3)(CO)_(3)] is

The oxidation state of chromium in Cr(CO)_(6) is ____

The oxidation state of central atom in the anion of compound NaH_(2)PO_(2) will be ……… .

The oxidation state of Barium in Ba(H_(2)PO_(2))_(2) is

The oxidation state of a substance increases in oxidation and decreases in reduction.

The oxidation state of a substance in its elementary state is equal to

The oxidation sate of +3 for phosphorus is in

The oxidation product of ethylene by air at 200-400^(@)C in presence of silver catalyst is

The oxidation potential of A and B are + 2.37 and+ 1.66 V respectively.In a chemical reaction

The oxidation of benzene by V_(2)O_(5) in the presence of air produce :

The oxidation of an alcohol (C_(5)H_(12)O) with acid dichromate gives a mixture of dimethyl ketone and acetic acid. The alcohol is