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This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 1001. |
Which of the following is not correct ?A. In Nelson method of NaOH preparation , `Cl_(2)` is liberated at anode .B. With hot and conc. NaOH , `Cl_(2)` gas gives `NaClO_3`C. NaOH reacts with white phosphorous to give phosphineD. NaOH is used in rayon industry |
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Answer» Correct Answer - B `underset("Hot + conc. ")(6NaOH) +3Cl_(2) to 5NaCl + underset(" Sodium chlorate ")(NaClO_(3))+3H_(2)O` |
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| 1002. |
What is X in the following reaction `KHSO_4+F_2rarrHF+X`A. `K_(2)SO_(4)`B. `K_(2)S_(2)O_(4)`C. `K_(2)S_(2)O_(2)`D. `K_(2)S_(2)O_(8)` |
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Answer» Correct Answer - D `2KHSO_(4) +F_(2) to 2HF + underset(X)(K_2S_(2)O_(6))` |
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| 1003. |
Which is not produced when `Nl_(3)NH_(3)` is rubbed against the hard surface ?A. `l_(2)`B. `N_(2)`C. `NH_(3)`D. `NH_(4)l` |
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Answer» Correct Answer - C `8NH_(3)Nl_(3) to 5N_(2)+9l_(2)+6NH_(4)l` |
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| 1004. |
Colour of the solution when KI reacts with `Br_(2)` isA. blueB. blackC. redD. no change |
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Answer» Correct Answer - B Bromine liberates iodine from KI solution because of its oxidising property . Colour of iodine is grey black so , black colour is obtined . `2KI+Br_(2) to 2KBr +I_2` |
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| 1005. |
Which of the following product is formed by the reaction of sulphur dioxide with chlorine in the presence of sunlight ?A. `SO_(2)Cl `B. `SO_(2)Cl_(2) `C. `SOCl_2`D. `SO_3Cl ` |
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Answer» Correct Answer - B `SO_(2)+ Cl_(2) overset(hv )to underset("Sulphuryl chloride ")(SO_(2)Cl_(2))` |
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| 1006. |
Which will not give precipitate with `NH_(4)OH` Solution ?A. `FeCl_(3)`(aq)B. `Al_(2)(SO_(4))_(3)`(aq)C. `CuSO_(4)`(aq)D. `CrCl_(3)`(aq) |
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Answer» Correct Answer - C `CuSO_(4)` (aq) form a soluble complex with `NH_(4)OH` `CuSO_(4)+4NH_(4)OH` to `underset("Soluble")([Cu(NH_(3))_(4)])SO_(4)+4H_(2)O` |
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| 1007. |
Which is the coordinating solvent in the following reactions ? `BF_(3)+HF+H_(2)O to H_(3)O^(+)+BF_(4)^(-)`A. HFB. `H_(2)O`C. `NH_(3)`D. `BF_(3)` |
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Answer» Correct Answer - A HF acts as a coordinating solvent . It loses proton and F forms coordinate bond with `BF_(3)` . |
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| 1008. |
Which of the following cannot result in the formation of `NO` ?A. `N_(2)+O_(2)` (Electric arc)B. `NH_(3)+O_(2),(Pt//Rh catalyst// 1200 K)`C. `NaNO_(3)//HCl`D. None of these |
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Answer» Correct Answer - C The reaction of `NaNO_(3)` and `HCl` do not give `NO`. `NaNO+"HCl"toNaCl+HNO_(3)," "4HNO_(3)to H_(2)O+NO_(2)+O_(2)` |
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| 1009. |
A lighting flash through air may result in the formation of :A. nitrogen pentaoxideB. ammoniaC. nitric acidD. nitric oxide |
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Answer» Correct Answer - D `underset(("From air"))(N_(2)+O_(2))overset("Electric disch arge ")to 2NO` |
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| 1010. |
The dipole moment of `H_(2)O_(2)` is more than that of `H_(2)O` but `H_(2)O_(2)` is not a good solvent because `:`A. It has a very high dielectric constant so that ionic compounds cannot be dissolved in itB. It dows not act as an oxidising agentC. It acts as a reducing agent.D. It dissociates easily and acts as an oxidising agent in chemical reactions. |
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Answer» Correct Answer - 4 `H_(2)O_(2)` is thermally unstable and it decomposes easily. `H_(2)O_(2)(l)rarrH_(2)O(l)+(1)/(2)O_(2)(g)` Its decomposition is catalysed by alkali metals present in traces in the glass of the vessel. |
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| 1011. |
Which is the correct sequence in the following properties. For the correct order mark `( T)` and for the incorrect order mark `( F) :` `{:((a)"Acidity order ":SiF_(4) lt SiCl_(4) lt SiBr_(4) lt Sil,,(b)"Melting point":NH_(3) gt SbH_(3) gt AsH_(3) gt PH_(3),,),((c )"Boiling point " :NH_(3) gt SbH_(3) gt AsH_(3) gt PH_(3),,(d)"Dipole moment order ":NH_(3) gt SbH_(3) gt AsH_(3) gt PH_(3),=,5):}`A. `F T F T`B. `T F T F`C. `F F T T `D. `F F T F` |
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Answer» Correct Answer - A `(a) (F),` As the size of halogen atom increases crowding on Si atom will increases, hence, tendency of attack of Lewis base decreases. `(b)(T), M.P.` of `NH_(3)` is highest due to intermolecular `H-` bonding in it. Next lower `M.P.` will be of `SbH_(3)` follofwed by `AsH_(3)` due to high mol. wt. of `SbH_(3)`. (c) (F) `M.P.` and `B.P.` of increase from `PH_(3)` to `AsH_(3)` due to increase in mol. wt. `NH_(3)` does not follow this trend due to iner molecular H-bonding. (d) (T), Value of bond moment decreases. |
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| 1012. |
The wrong statement about `N_(2)O` is :A. it is nitrous oxideB. it is least reactive oxide of nitrogenC. it is not a linear moleculeD. it is known as laughing gas |
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Answer» Correct Answer - C `:Nequivunderset(sp)(N)rarrunderset(..)ddotO: harr underset(..):barN=underset(sp)overset(+)N=underset(..)overset(..)Oharr:N equivunderset(sp)overset(+)(N)-underset(..)oversetoverset(bar)(..)O:` (linear) |
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| 1013. |
Which of the following does not give `NO_(2)` by heating at `500^(circ)C` ?A. `NaNO_(3)`B. `Pb(NO_(3))_(2)`C. `Cu(NO_(3))_(2)`D. `AgNO_(3)` |
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Answer» Correct Answer - A `2NaNO_(3)overset(Delta)to2NaNO_(2)+O_(2)` |
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| 1014. |
Which is not correct for `N_2O` ?A. It is laughing gas and is used as anaesthetic agentB. It is nitrous oxideC. It is not a linear moleculeD. It is least reactive of all the oxides of nitrogen |
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Answer» Correct Answer - C `N-=N to O` - Linear Molecule |
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| 1015. |
Which of the following on heating produces `NO_(2) ` ?A. `NaNO_(3)`B. `AgNO_(3)`C. `NH_(4)NO_(3)`D. `NH_(4)NO_(2)` |
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Answer» Correct Answer - 2 `AgNO_(3)rarrAg+(1)/(2)O_(2)+NO_(2)" "," "2NaNO_(3)overset(500^(@)C)rarr2NaNO_(2)+O_(2)` `4NaNO_(3)overset(800^(@)C)rarr2Na_(2)O+5O_(2)+2N_(2)` |
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| 1016. |
In `NO_(3)^(-)` ion, the number of bond pair and lone pair of electrons on nitrogen atom are:A. 4, 0B. 1,2C. 3,1D. 2, 2 |
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Answer» Correct Answer - A `NO_3^(-) " " .^(-)O-undersetOundersetdarrN=O` Bond pair 4 , lone pair 0 |
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| 1017. |
Which of the following statements is wrong?A. Nitrogen cannot form `dpi-ppi` bondB. The stability of hydrides increase from `NH_(3) to BiH_(3)` in group `15` of the periodic tableC. Single `N-N` bond is weaker than the single `P-P` bondD. `N_(2)O_(4)` has two resonance structure |
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Answer» Correct Answer - B Stability of hydrides increases from `NH_(3)` to `BiH_(3)`. `:.` The correct order is `NH_(3)ltPH_(3)ltAsH_(3)ltSbH_(3)ltBiH_(3)` |
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| 1018. |
When lightning flash is produced, which gas is formed?A. Nitrous oxideB. Nitrogen dioxideC. Dinitrogen pentoxideD. Nitric oxide |
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Answer» Correct Answer - D in upper atmoshphere `NO` is formed by lightning flash. `N_(2)+O_(2) hArr 2NO` |
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| 1019. |
Which is the best decription of behaviour of bromine in the reaction given below ? `H_(2)O + Br_(2) HBR + HOBr`A. Only oxidisedB. Only reducedC. Both oxidised and reducedD. Only proton accepted |
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Answer» Correct Answer - C In the reaction. `H_(2)O+overset(0)(B)r_(2) rarr HO overset(+1)(Br)+Hoverset(-1)(Br)` The oxidation number of bromine increases from 0 to +1 and decreases from 0 to -1, dut to this reason bromine is both oxidised as well as reduced in the above reaction. |
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| 1020. |
How is nitric oxide (NO) prepared ? |
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Answer» The catalytic oxidation of `NH_(3)` by atmospheric oxygen gives nitric oxide. `4"NH"_(3(("aq")))+5"O"_(2_((g)))underset(500"K",9"bar")overset("Pt")to4"NO"_((g))+6"H"_(2)"O"_((g))` |
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| 1021. |
Distillation of HBr and `HBrO_3` yields bromine gas. |
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Answer» Correct Answer - T |
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| 1022. |
`Pl_3` on hydrolysis yields `H_3PO_3` and HI |
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Answer» Correct Answer - T |
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| 1023. |
Which of the following is not correct for `N_(2)O`?A. It is called laughing gasB. It is nitrous oxideC. It is not a linear moleculeD. It is least reactive in all oxides of nitrogen |
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Answer» Correct Answer - C `N_(2)O` is a linear molecule |
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| 1024. |
`IO_(3)^(-) + 6OH^(-)+Cl_(2) to IO_(6)^(5-) ("periodate")+3H_2O+2Cl^(-)` |
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Answer» Correct Answer - T |
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| 1025. |
`P_(4)O_(10)` is the anhydride of the followingA. `H_(3)PO_(2)`B. `H_(3)PO_(3) `C. `H_(3)PO_(4)`D. `H_(4)P_(2)O_(7)` |
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Answer» Correct Answer - C `4H_3PO_(4) overset(Delta)to P_4O_(10)+6H_2O` |
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| 1026. |
HBr is a stronger acid than HI because of hydrogen bonding. |
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Answer» Correct Answer - F |
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| 1027. |
`HBr//HI` are prepared by heatingA. Sodium, `Br_(2)//I_(2)` and waterB. Phosphorus `Br_(2)//I_(2)` and waterC. Potassium, `Br_(2)//I_(2)` and waterD. Selenium, `Br_(2)//I_(2)` and water |
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Answer» Correct Answer - B Bromine reacts with `s,P,As……..` `2P+3Br_(2)rarr2PBr_(3)` Iodine react with `P,Fe,K` `2P+3I_(2)rarr2PI_(3)` |
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| 1028. |
`HBr//HI` are prepared by heatingA. Bromide/iodide respectively with conc. `H_(2)SO_(4)`B. Bromide/iodide respectively with conc. `HPO_(3)`C. Bromide/iodide respectively with conc. `H_(3)PO_(4)`D. Bromide/iodide respectively with dil. `HPO_(3)` |
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Answer» Correct Answer - A `2MBr+H_(2)SO_(4)overset(Delta)rarrM_(2)SO_(4)+2HBr` `2MI+H_(2)SO_(4)overset(Delta)rarrM_(2)SO_(4)+2HI` `M=Na,K` |
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| 1029. |
Of the following compounds, the most acidic isA. `As_2O_(3)`B. `P_(2)O_(5)`C. `Sb_(2)O_(3)`D. `Bi_(2)O_(3)` |
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Answer» Correct Answer - B Acidic strength of oxides decreases along a group from upward to downward . Thus ,the order of acidic strength is `P_2O gt As_2O_3 gt Sb_2 O_3 gt Bi_2O_3 ` |
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| 1030. |
How is ozone prepared from oxygen ? Explain its reaction with KI |
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Answer» Preparation of Ozone : A slow dry stream of oxygen under silent electric discharge to form ozone (about `10%`) The product obtained is known as ozonised oxygen. `3O_(2)to2O_(3) DeltaH^(@)=142"kJ"//"mole"` `to` The formation of ozone is an endothermic reaction. `to` It is necessary to use silent electric discharge in the preparation of `O_(3)` to prevent its de composition Reaction with KI : moist KI is oxidised to Iodine in presence of ozone. `2KI+H_(2)O+O_(3)to2KOH+I_(2)+O_(2)` |
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| 1031. |
How is ozone prepared ? How does it react with the following ? PbS |
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Answer» Preparation of Ozone : A slow dry stream of oxygen under silent electric discharge to form ozone (about `10%`) The product obtained is known as ozonised oxygen. `3O_(2)to2O_(3) DeltaH^(@)=142"kJ"//"mole"` `to` The formation of ozone is an endothermic reaction. `to` It is necessary to use silent electric discharge in the preparation of `O_(3)` to prevent its decomposition Reaction with PbS : Black lead sulphide oxidised to white lead sulphate in presence of ozone. `PbS+4O_(3)toPbSO_(4)+4O_(2)` |
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| 1032. |
`PCl_(3)` on hydrolysis givesA. `HPO_(3)`B. `H_(3)PO_(2) `C. `H_(3)PO_(4)`D. `H_(3)PO_(3)` |
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Answer» Correct Answer - D `3H_2O+PCl_(3) to H_3PO_(3)+3HCl ` |
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| 1033. |
Which of the following will be obtained on heating orthophosphorous acid ?A. Metaphosphoric acidB. phosphorous acidC. Hypophosphorous acidD. Phosphine |
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Answer» Correct Answer - D `underset("Orthosphosphorous acid ")(4H_3PO_3) overset(Delta)to underset("Orthophosphoric acid ")(3H_3PO_4)+underset("Phosphine")(PH_(3))` |
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| 1034. |
Write any two compounds, in which oxygen shows an oxidation state different from -2. Give the oxidation states of oxygen in them. |
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Answer» `OF_(2)` and `O_(2)" "F_(2)` are two compounds in which oxygen shows an oxidation state different from - 2. `to` In `OF_(2)` the oxidation state of oxygen is +2. `to` In `O_(2)F_(2)` the oxidation state of oxygen is +1. |
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| 1035. |
Glass is a:A. liquidB. solidC. supercooled liquidD. transparent-organic polymer |
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Answer» Correct Answer - C Glass is an example of amorphous solid. It is also known as supercooled liquid. Glass have short range order of constituents. |
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| 1036. |
How does `SO_(2)` react with the following ? `Cl_(2)` |
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Answer» `SO_(2)` gas reacts with chlorine gas in the presence of charcoal to form suphuryl chloride. `SO_(2(g))+Cl_(2(g))toSO_(2)Cl_(2(l))` |
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| 1037. |
Explain the following reaction between `"PCl"_(3)` and `H_(3)PO_(3)`. |
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Answer» `"PCl"_(3)` undergoes hydrolysis to form `H_(3)PO_(3)` `"PCl"_(3)+3"H"_(2)"O"to"H"_(3)"PO"_(3)+3"HCl"` |
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| 1038. |
What happens when `SiO_(2)` is reacted with following ? (a) KOH, (b) `CaCO_(2)`, (c ) `KNO_(3)`, (d) HF (e ) Coke |
| Answer» Correct Answer - Silicates are formed | |
| 1039. |
What is silica garden ? |
| Answer» Correct Answer - When transitions metals are added into soda glass solution. Different type of colour are obtained | |
| 1040. |
Silica is soluble inA. HClB. `HNO_(3)`C. `H_(2)SO_(4)`D. `HF`. |
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Answer» Correct Answer - D Silica `(SiO_(2))` is soluble in HF. `SiO_(2)+4HFrarrSiF_(4)+2H_(2)O` `SiO_(2)+4HFrarrH_(2)SiF_(6)`. |
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| 1041. |
What is water glass?A. a thin layer of water on glass plateB. the fluid like flow of gasC. sodium silicate.D. borax soda glass. |
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Answer» Correct Answer - C Water glass is sodium silicate. |
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| 1042. |
Group 13 elements show +1 and +3 oxidation states. Relative statibility of +3 oxidation may be given asA. `Ti^(3+)gtIn^(3+)gtGa^(3+)gtAl^(3+)gtB^(3+)`B. `B^(3+)gtAl^(3+)gtGa^(3+)gtIn^(3+)gtTi^(3+)`C. `Al^(3+)gtGa^(3+)gtIn^(3+)gtB^(3+)`D. `Al^(3+)gtB^(3+)gtGa^(3+)Ti^(3+)gtIn^(3+)` |
| Answer» Stability of +3 oxidation state decreases down the group because of inerg pair effect. Therefore, it is the correct sequence | |
| 1043. |
The material used in solar cells containsA. CsB. SiC. SnD. Ti, |
| Answer» Silicon (Si) due to its emi-conducting nature is used in solar cells. | |
| 1044. |
How many atoms are linked through a bridges bond? |
| Answer» Correct Answer - Three atoms | |
| 1045. |
Why is boric acid considered as a weak acid ? |
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Answer» Boric acid `(H_(3)BO_(3))` is a very weak acid `(k_(a)= 1xx10^(-9))`. Infact, it is a Lewis acid and accepts andelectron pair from `OH^(-)` ion of `H_(2)O` molecule, thereby releasing a proton `(H^(+))`. Moreover. `B(OH)_(3)+H-Ohrarr[B(OH)_(4)]^(-)+H^(+)` the hydrogen atoms already present in the acid are trapped in hydrogen bonds an d cannot be released easily. For detaisl. Consult text part. |
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| 1046. |
Boron is unable to form `BF_(6)^(3-)` ion. Explain. |
| Answer» Due to absence of d-orbitals, B at the maximum can ammoundates 8 electrons pairs of electrons in its valences shell. In other words, B can have a maximum convalency of 4. Therefore, `BF_(3)` can form `BF_(2)` but never `BF_(6)^(3-)` in which the covalency of B is 6. | |
| 1047. |
Boron is unable to form `BF_(6)^(3-)`– ion. Explain. |
| Answer» The electronic configuration of boron (Z=5) `1s^(2)2s^(2)2p_(x)^(1)`. It can show a maximum covalency of four in its compounds since no d-orbtials are available in the valence shell. In case of boron. `BF_(6)^(3-)` ion can not be formed. | |
| 1048. |
Which is the strongest Lewis acid?A. `BF_(3)`B. `BCl_(3)`C. `BBr_(3)`D. `Bl_(3)`. |
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Answer» Correct Answer - D `BI_(3)` is strongest Lewis acid because of least back bonding. |
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| 1049. |
Manufacture of phophoric acid from phosphorus. |
| Answer» Correct Answer - A::B::C::D | |
| 1050. |
Describe the action of heat on `NaHSO_(3)` |
| Answer» Correct Answer - A::B::C::D | |