InterviewSolution
Saved Bookmarks
InterviewSolution
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.
| 651. |
In qualitative analysis when `H_(2)S` is passed through an aqueous solution of salt acidified with dil. HCl, a black precipitate is obtained. On boiling the precipitate with dil. `HNO_(3)`, it forms a solution of blue colour. Addition of excess of aqueous solution of ammonia to this solution givesA. deep blue precipitate of `Cu(OH)_(2)`B. deep blue solution of `[Cu (NH_(3))_(4)]^(2+)`C. deep blue solution of `Cu(NO_(3))_(2)`D. deep blue solution of `Cu(OH)_(2). Cu (NO_(3))_(2)` |
|
Answer» Correct Answer - B It is the correct answer. |
|
| 652. |
Lithium fluroide (LiF) is mainly ionic but lithium iodide (LiI) is covalent in nature. Assign reason. |
| Answer» `I^(-)` ion has a bigger size than the `F^(-)` ion. It can be more readily polarised by `Li^(+)` ion than by `F^(-)` ion. As a result, `Li^(+) " and " I^(-)` ions come quite close and neutralise their charge to a large extent resulting in covalent compound. On the other hand, `Li^(+) " and " F^(-)` ions are not in a position to neutralise their charge and LiF is mainly ionic. | |
| 653. |
`Ka_(1), Ka_(2)` and `Ka_(3)` are the respective constants for the following reactions `H_(2)S hArr H^(+) + HS^(-)` `HS^(-) hArr H^(+) + S^(2-)` `H_(2)S hArr 2H^(+) + S^(2-)` The correct relationship between `Ka_(1), Ka_(2)` and `Ka_(3)` is |
|
Answer» The dissociation of sulphuric acid in aqueous solution may be expressed as : `H_(2)SO_(4)(aq) +H_(2)O (l) to H_(3)O^(+) (aq) +HSO_(4)^(-) (aq) , Ka_(1) gt 10` `HSO_(4)^(-) (aq) +H_(2)O (l) to H_(3)O^(+)(aq) +SO_(4)^(2-) (aq) , Ka_(2)=1.2xx10^(-2)` `HSO_(4)^(-)` ion left when the acid loses a proton, is negatively charged. It has lesser tendency to donate a proton to `H_(2)O` molecule. |
|
| 654. |
A metal X reacts with aqueous NaOH solution to form Y and a highly inflammalbe gas. Solution Y is heated and `CO_(2)` is poured through it. Z precipitates out and `Na_(2)CO_(3)` is formed. Z on the heating gives `AI_(2)O_(3)`. Identify X,Y and Z. X Y ZA. `Al, NaAIO_(2), AI(OH)_(3)`B. `AI_(2)O_(3), NaAIO_(2), AI_(2)CO_(3)`C. `AI_(2)O_(3), [Na_(2)AIO_(2)]^(+) OH^(-), AI(OH)_(3)`D. `AI, AI(OH)_(3) AI_(2)O_(3)` |
|
Answer» Correct Answer - A `underset((X))(2AI) + 2NaOH + 2H_(2) O to underset((Y))(2NaSIO_(2)) + 3H_(2)` `underset((Y))(2NaAIO_(2)) + CO_(2) + 3H_(2)O to underset((Z))(2AI(OH)_(3)) + Na_(2) CO_(3)` `underset((Z))(2AI(OH)_(3)) to AI_(2)O_(3) + 3H_(2) O` |
|
| 655. |
An orange solid `(A)` on heating gave a green residue `(B)`, colourless gas `( C)` and water vapour. The dry gas `( C)` on passing over heated magnesium gave a white solid `(D).(D)` on reaction with water have a gas `( E)` which formed dense white fumes with `HCl`. Indentify `(A)` to `( E)` and give the reactions.A. sodium dichromateB. potassium dichromateC. potassium chromateD. ammonium dichromate. |
|
Answer» Correct Answer - D Orange solid is ammonium dichromate i.e., `(NH_(4))_(2)Cr_(2)O_(7)`. |
|
| 656. |
Assign reason for the following : (i) `H_(3)PO_(2)` is a stronger reducing agent than `H_(3)PO_(4)`. (ii) Sulphur shows more tendency for catenation than oxygen. (iii) Reducing character increases from HF to HI. |
| Answer» In `H_(3) overset(+1)(PO_(2))`, the oxidation state of P can increase upon `+5`. But in `H_(3) overset(+5)(PO_(4))`. P atom is already in highest oxidation state `(+5)`. Therfore, `H_(3)PO_(2)` acts as stronger reducing agent than `H_(3)PO_(4)`. In fact, the latter can act only as oxidising agent. | |
| 657. |
Indicate whether the following statements are true or false. Explain your answer in brief. (i) The decreasing order of electron affinity of F, Cl, Br is FgtClgtBr. (ii) HBr is stronger acid than Hl because of hydrogen bonding. |
|
Answer» (i) false (ClgtFgtBr) (ii) False. (Hl is stronger acid tha HBr because l atom is bigger than Br atom. As a result bond dissociation energy of H-l is less). |
|
| 658. |
The pair in which phosphours atoms have a formed oxidation state of `+3` isA. orthophosphorus and pyrophosphorus acidsB. pyrophosphorus and hypophosphoric acidsC. orthophosphorus and hypophosphoric acidsD. pyrophosphorus and pyrophosphoric acids |
|
Answer» Correct Answer - A `{:("Name","Formula","Oxidation state of P"),("Orthophosphorus acid",H_(3)PO_(3)," "+3),("Pyrophosphorus acid",H_(4)P_(2)O_(5)," "+3),("Hypophosphoric acid",H_(4)P_(2)O_(6)," "+4),("Pyrophosphoric acid", H_(4)P_(2)O_(7)," "+5):}` Therefore, (a) is the correct option. |
|
| 659. |
`BF_(3)` is used as a catalyst in various organic reactions becauseA. it is a strong reducing agentB. it is a highly reactive compoundC. it is a weak Lewis acidD. it is a strong Lewis acid. |
| Answer» Correct Answer - D | |
| 660. |
The reaction of zinc with dilute and concentrated nitric acid, respectively, produceA. `N_(2)O " NO_(2)`B. `NO_(2) " and " NO`C. `NO " and " N_(2)O`D. `NO_(2) " and " N_(2)O` |
|
Answer» Correct Answer - A `4Zn+10HNO_(3)(aq) to 4 Zn(NO_(3))_(2)+N_(2)O+5H_(2)O` `Zn+ 4 HNO_(3)("conc.") to Zn (NO_(3))_(2)+2NO_(2)+2H_(2)O` |
|
| 661. |
Name the product when zinc is reacted with very dilute `HNO_(3)` acid. |
| Answer» `Zn(NO_(3))_(2) " and " NH_(4)NO_(3)` | |
| 662. |
Zinc reacts with dilute `H_(2)SO_(4)` to give `H_(2)`. It also reacts with conc. `H_(2)SO_(4)` to give `SO_(2)` . How will you account for this difference ? |
|
Answer» Dilute `H_(2)SO_(4)` behaves as a proton acid and zinc metal displaces hydrogen from the acid. `Zn+H_(2)SO_(4)("dil")to ZnSO_(4)+H_(2)` Concentrated `H_(2)O_(4)` behaves as a strong oxidising agent and itself is reduced to `SO_(2)`. `Zn +2H_(2)SO_(4) ("conc.")to ZnSO_(4)+SO_(2)2H_(2)O`. |
|
| 663. |
A water soluble compound of a posisonous element M when heated with `Zn//H_(2)SO_(4)` gives a colourless and extremely posisonous gaseous compound N which when passed through a heated tube gives a silvery mirror of element M. Identify M and N. |
|
Answer» The psisonous element M is likely to be arenic (As) and the water soluble compound is `AsCl_(3)`. On the basis of available data, the following reactions are feasible. `underset(("Soluble compound"))underset((M))(AsCl_(3))+6H overset(Zn//HCl)to underset(("Poisonous gas"))underset((N))(AsH_(3))+3HCl` `2AsH_(3)overset("heat")to underset((M))(2As)+3H_(2)` |
|
| 664. |
which of the following reaction gives reasonably pure `NO`?A. `3KNO_(2)(l)+KNO_(3)(l)+Cr_(2)O_(3)(s)rarr2K_(2)CrO_(4)+4NO`B. `2NaNO_(2)+2FeSO_(4)+3H_(2)SO_(4)rarrFe_(2)(SO_(4))_(3)+2NaHSO_(4)+2H_(2)O+2NO`C. `2NaNO_(2)+2NaI+4H_(2)SO_(4)rarrI_(2)+4NaHSO_(4)+2H_(2)O+2NO`D. all o these |
|
Answer» Correct Answer - 4 Each of these reactions gives reasonably pure nitric oxide. |
|
| 665. |
Repeated use of which one of the following fertilizers would increase the acidity of the soil?A. potassium nitrateB. UreaC. Superphosphate of limeD. Ammonium sulphate |
|
Answer» Correct Answer - 4 Becauase ammonium sulphate a sallt of weak base `(NH_(3))` and strong acid `(H_(2)SO_(4))` undergoes hydrolysis to yield an acidic solution. Superhosphate is a mixture of calcium tetrahydrogen diorthoposhphate and calcium sulphate made by treating mineral phosphate with concentrated sulphiric acid: `Ca_(3)(PO_(4))_(2)+2H_(2)SO_(4)rarr underbrace(Ca(H_(2)PO_(4))_(2)+2CaSO_(4))_("Superphosphate")` The diphosphate salt is more soluble than untreated mineral phosphates and is therefore more easily assimilated by plants. An improved product is obtained by treating mineral phosphate with orthophosphoric acid instead of sulphuric acid: `Ca_(3)(PO_(4))_(2)+4H_(3)PO_(4) rarr 3Ca(H_(2)PO_(4))_(2)` This fertilixers called tripke superphosphate because its phosphate content is about three times that of ordinary superphosphate fertilizer is preferred because it lowers fright costs: |
|
| 666. |
A mixture `Al(OH)_(3) and Fe(OH)_(3)` is given to you. How would you separate it?? |
|
Answer» It can be easily separated by the use of conc. NaOH solution. Which reacts only with `Al(OH)_(3)` and forms soluble sodium metaaluminate. `Fe(OH)_(3)` will remain in the residue `Al(OH)_(3)+NaOHto NaAlO_(2)+2H_(2)O` |
|
| 667. |
When conc. `H_(2)SO_(4)` was added to an unknown salt present in a test which was heated, a brown gas (A) was evolved. The gas intenstified when copper turning were also added into the test tube. On cooling, the gas (A) changed into a colourless liquid (B). (a) Identify the gases A and B (b) Write equations for the reactions involved. |
|
Answer» The available data suggests that the salt is some nitrate of a metal and the chemical reactions involved are listed : `MNO_(3)+H_(2)O("conc.") overset("Heat")to MHSO_(4)+HNO_(3)` `4HNO_(3)overset("Heat")to underset((A))underset("Brown gas") (4NO_(2)+2H_(2)O+O_(2))` Upon adding some copper turning, more fumes of gas (A) were evolved and therefore, the brown colour was intestified. `Cu+4HNO_(3) overset("Heat")to Cu(NO_(3))_(2)+2H_(2)O+2NO_(2)` `underset((B))underset("Brown gas")(2NO_(2))underset("Heat")overset("Cool")harr underset((B))underset("Colourless liquid")(N_(2)O_(4))` |
|
| 668. |
Which of the following compounds of broine is used as a gasoline additive?A. `CHBr_(2)`B. `CBr_(4)`C. `BrCH_(2)CH_(2)Br`D. `CH_(3)CHBr_(2)` |
|
Answer» Correct Answer - 3 The main outlet for bromine is ethylene bromide `(BrCH_(2)CH_(2)Br)` which is used as a gasoline additive. Bromine is also used to make `AgBr` for photography. |
|
| 669. |
In quantitative ananlysis ,ammonia is used to separateA. `FeCl_(3)` from `AlCl_(3)`B. `PbCl_(2)` and `Mg(OH)_(2)`C. `NaCl` and `KCl`D. `AgCl` and `Hg_(2)Cl_(2)` |
|
Answer» Correct Answer - 4 Because silver chloride dissolves in `NH_(4)OH` solution `AgCl+2NH_(4)OHrarr[Ag(NH_(3))_(2)]Cl+2H_(2)O` |
|
| 670. |
Diborane upon hydrolysis givesA. `H_(3)BO_(2) + H_(2)O_(2)`B. `H_(3)BO_(3) + H_(2)`C. `B_(2)O_(3) + O_(2)`D. `H_(3)BO_(3) + H_(2) O_(2)` |
|
Answer» Correct Answer - B `B_(2)H_(6) + 6 H_(2)O to 2H_(3) BO_(3) + 6H_(2)` |
|
| 671. |
Which of the following gases is evolved when urea is heated with `NaOH`?A. `N_(2)O`B. `NO`C. `NH_(3)`D. `N_(2)` |
|
Answer» Correct Answer - 3 Urea on heating with caustic sode forms ammonia: `H_(2)NCONH_(2)+2NaOH rarr Na_(2)CO_(3)+2NH_(3)` |
|
| 672. |
An aqueous solution of boric acid is found to be weakly acidic in nature. This acidic character arises due to the following reasons.A. It is a protic acid which donates protons in aqueous solution.B. It is a Lewis acid which abstracts `OH^(-)` from water and leaves `H^(+)` to make to solution acidicC. It gives metaboric acid when dissolved in water.D. It is prepared by reaction of borax with sulphuric acid hence it behaves as an acid. |
|
Answer» Correct Answer - B It reacts with water to abstract `OH^(-)` ions and releases `H_(3)O^(+)` ion making it acidic. |
|
| 673. |
What happen when diborane reacts with Lewis bases?A. It forms boron trihydride `(BH_(3))` due to cleavage.B. It undergoes cleavage to give borane adduct `BH_(3)L` (Where, L = Lewis base)C. It oxidises to give `B_(2) O_(3)`D. It does not react with Lewis bases |
|
Answer» Correct Answer - B `B_(2)H_(6) + underset(("Lewis base"))(2L) to underset("Adduct")(2BH_(3).L)` or `B_(2)H_(6) + 2NMe_(3) to 2NH_(3). Nme_(3)` |
|
| 674. |
How can you explain higher stability of `BCI_(3)` as compared to `TICI_(3)`? |
| Answer» Boron and thallium belong to group 13 of the periodic table. In this group, the +1 oxidation state becomes more stable on moving down the group. `BCl_(3)` is more stable tha `TlCl_(3)` because the +3 oxidation state of B is more stable than the +3 oxidation state of Tl. In Tl, the +3 state is highly oxidising and it reverts back to the more stable +1 state. | |
| 675. |
Which of the following compounds are formed when `BCI_(3)` is treated with water?A. `H_(3)BO_(3)`B. `b_(2)H_(6)`C. `B_(2)O_(3)`D. `HBO_(2)` |
|
Answer» Correct Answer - A `BCI_(3) + 3H_(2) O to H_(3)BO_(3) + 3HCI` |
|
| 676. |
Chlorine water has both oxidising as well as bleaching properties properties ? Explain. |
|
Answer» Chlorine reacts with water to evolve nascent oxygen which brings about both oxidation and bleaching. As oxidsing agent: `(Cl_(2)+H_(2)O to 2HCl+O)/underset(Cl_(2)+SO_(2)+2H_(2)Oto 2HCl +H_(2)SO_(4))(SO_(2)+H_(2)O +O to H_(2)SO_(4))` As bleaching agent : `Cl_(2)+H_(2)O to 2HCl+(O)` Coloured substance `+(O) to ` Colourless product |
|
| 677. |
Chlorine is used for the bleaching ofA. paperB. pulpC. textilesD. all of these |
|
Answer» Correct Answer - 4 It is also used as disinfectant for sterilising drinking water and in the production of organic compounds (e.g polyvinyl chloride,chlorinated hydrocarbons ,pharmaceuticals herbicides ,pesticides) and inorganic compounds (e.g `HCl, PCl_(3)` and `NaOCl`). |
|
| 678. |
`NH_(4)CI` is used to clean metal surface becauseA. `NH_(4)Cl` is a volatile compoundB. `NH_(4)Cl` forms a souble complex with metalC. on warming it dissociates into `NH_(3)` and `HCl`D. it is coloureless |
|
Answer» Correct Answer - 3 `NH_(4)Cl overset("Heat")rarrNH_(3)+HCl` `HCl` cleans the surface of the metal. |
|
| 679. |
The most abundant compounf of `CI` isA. `NaCl`B. `NaCIO_(3)`C. `NaOCl`D. `NaCIO_(4)` |
|
Answer» Correct Answer - 1 The main source is chlorine is sodium chloride, which occur in sea water and in salt deposits (e.g. the Dead Sea and Stassfurt deposite and the rock salt deposits in Cheshire. Electrolysis of an aqueous solutions of sodium chloride produces sodium hydroxide chlroine adn hydrogen. |
|
| 680. |
Ammonia acts as a ligand. Discuss. |
| Answer» Ammonia `(overset(* *)(NH_(3)))` has lone pair of electrons on the nitrogen atom and is a Lewis base. Since it can easily donate the electron pair, ammonia acts as a ligand and forms co-ordination bonds with electron deficient species. | |
| 681. |
Which of the following has least covalent `P-H` bondA. `PH_(4)^(+)`B. `P_(2)H_(5)^(+)`C. `P_(2)H_(6)^(2+)`D. `PH_(3)` |
|
Answer» Correct Answer - 3 the covalent charter of `P-H` bond depends on the formal charge distributed on each `P-H` bond In `PH_(4)^(+)` it is `+1//4=+0.25,` in `P_(2)H_(5)^(+)` it is `+1//5=+0.2` and in `P_(2)H_(6)^(2+)` it is `+2//6=+0.33`. The higher the formal charge the lesser the covalent character due to more polarisation .Thus the least covalent `P-H` bond is present in `P_(2)H_(6)^(2+)`. |
|
| 682. |
If (C) is silicone, then answer the following questions. Q. (A) and (B) areA. `R_(2)SiCl_(2)&R_(2)Si(OH)_(2)`B. `R_(2)SiCl_(2)&R_(2)Si=O`C. `RSiCl_(3)&Rsi(OH)_(3)`D. `RSiCl_(3)&R overset(O)overset(||)(S)i-OH` |
| Answer» Correct Answer - C | |
| 683. |
Apart from `N_(2)O` which other colourless gas supports combustion ? |
| Answer» Correct Answer - `O_(2)` | |
| 684. |
If (C) is silicone, then answer the following questions. Q. Mode by which polymerisation is undergoing isA. AdditionB. SubstitutionC. EliminationD. Condensation. |
| Answer» Correct Answer - D | |
| 685. |
Active nitrogen can be made by passing an electric spark through `N_(2)` gasA. at ordinary pressureB. at a very low temperatureC. at a very low pressure (2 mm Hg)D. at a high pressure |
|
Answer» Correct Answer - 3 When the electric discharge is allowed to pass thorugh diintrogen under very low pressure (about `2`mm `Hg`) a brilliant yellow pink luminescense is observed which persists for some time after stoppage of the discharge .It is observed that dinitrogen after the discharge is more active this from of nitrogen is termed active nitrogen and it contains some nitrogen in the atomic state. It reacts readily with number of metals to form nitrides. It reacts with many nometals such as sulphur ,phosphorous iodine etc. It is able to break many normally stable molecules. |
|
| 686. |
Ammonia on reaction with hyprochlorite ions can formA. `N_(2)H_(4)` and `NH_(4)Cl`B. `HNO_(3)` and `NH_(4)Cl`C. `N_(2)` and `N_(2)H_(4)`D. `NO` and `N_(2)H_(4)` |
|
Answer» Correct Answer - 1 Hypochlorite ion oxidise `NH_(3)` to nitrogen `2NH_(3)+3NaClOrarrN_(2)+3NACl+H_(2)O` When the large excess of aqueous ammonia is treated with sodium hypochlorite in presence of glue or gelatine ,it gets oxidized to hydrazine (Raschig Process): `2NH_(3)+NaOClrarrunderset("Hydrazine")(NH_(2).NH_(2))+NaCl+H_(2)O` according the reaction processes in two steps ` NH_(3)+NaOCl overset("fast")rarrunderset("Chloramine")(NH_(2)Cl)+NaOH` `2NH_(3)+underset("Chloramine")(NH_(2)Cl)overset("slow")rarrNH_(2)NH_(2)+NH_(4)Cl` Glue or gelatine catalyses the slow reaction and prevents the oxidation of hydrazine to nitrogen ` N_(2)H_(4)+2NH_(2)ClrarrN_(2)+2NH_(4)Cl` |
|
| 687. |
The geometry of `SiO_(4)^(4-)` ion isA. TriangularB. TetrahedralC. Pentagonal bipyramidalD. Linear |
| Answer» Correct Answer - B | |
| 688. |
Nitrolim is a mixtrue ofA. `CaCN_(2)+N_(2)`B. `CaCN_(2)+` graphiteC. `CaCN_(2)+` diamondD. `CaC_(2)+` graphite |
|
Answer» Correct Answer - 2 The mixture of calcium cyanamide,`CaCN_(2)` and graphite ,`C`, is technically known as nitrolim. Calcium cyanamide a black crystalline power made by heating calcium dicarbide `CaC_(2)` in nitrogen at `1000^(@)C` `CaC_(2)+N_(2)overset(1000^(@)C)rarrCaNCN+C` It is used in large amounts as a nitrogenous fertillizer as it is converted by water in the soil into ammonia. `CaNCN+5H_(2)OrarrCaCO_(3)+2NH_(4)OH` It is used as a source of organic chemicals such as melamine. |
|
| 689. |
Nitrogen forms largest number of oxides in which oxidation state of nitrogen varies from +1 to +5 `N_(2)O,NO,N_(2)O_(3),N_(2)O_(4) and N_(2)O_(5)` respectively. The largest number of oxides are formed due to capability of forming stable multiple bonds by nitrogen with oxygen. Q. Which of the following statements is/are correct regarding oxides of nitrogen?A. Dinitrogen trioxide dissolves in KOH forming potassium nitrateB. Aqueous solution by nitrogen dioxide behave both as a reducing an as an oxidising agentC. Nitrous oxide is fairly soluble in cold water and turns blue litmus redD. Nitrogen dioxide is soluble in water to form nitric acid only |
| Answer» Correct Answer - B | |
| 690. |
Nitrogen forms largest number of oxides in which oxidation state of nitrogen varies from +1 to +5 `N_(2)O,NO,N_(2)O_(3),N_(2)O_(4) and N_(2)O_(5)` respectively. The largest number of oxides are formed due to capability of forming stable multiple bonds by nitrogen with oxygen. Q. Which of the following is/are correct statement(s)?A. In `N_(2)O_(4)` the N-N bond length is longer than the usual N-N single bond distanceB. `NO_(2)` molecule is angular and N-O bond length is intermediate between a single and a double bondC. `N_(2)O` is linear molecule and has small dipole momentD. All of these |
| Answer» Correct Answer - D | |
| 691. |
Nitrogen forms largest number of oxides in which oxidation state of nitrogen varies from +1 to +5 `N_(2)O,NO,N_(2)O_(3),N_(2)O_(4) and N_(2)O_(5)` respectively. The largest number of oxides are formed due to capability of forming stable multiple bonds by nitrogen with oxygen. Q. Which of the following oxides is known as anhydride of nitric acid?A. `N_(2)O_(5)`B. `N_(2)O_(3)`C. `NO`D. All of these |
| Answer» Correct Answer - A | |
| 692. |
What is the nature of `N^(3-)` ion ? |
| Answer» Lewis base forms acid `HN_(3)` | |
| 693. |
Name a compound of N, H and O which upon heating evolves nitrogen gas. |
| Answer» Correct Answer - `NH_(4)NO_(2)` | |
| 694. |
What is the formula of nitrolim ? |
| Answer» Correct Answer - `CaCN_(2)` | |
| 695. |
Why is bond angle in `PH_(4)^(+)` ion higher than in `PH_(3)` ? |
| Answer» `PH_(4)^(+)` ion is tetrahedral while `PH_(3)` is pyramidal in shape. | |
| 696. |
What are the shapes of `PH_(3)` molecule and `PH_(4)^(+)` ion ? |
| Answer» `PH_(3)` is pyramidal , `PH_(4)^(+)` is tetrahedral | |
| 697. |
What is the maximum oxidation state shown by nitrogen in its compounds ? |
| Answer» Correct Answer - `+5` | |
| 698. |
Can `PCl_(5)` act as oxidising as well as reducing agent ? Justify. |
|
Answer» In general, the molecules of a substance can behave as a reducing agent if the central atom is in a position to increase its oxidation number. Similarly, they can act as an oxidising agent if the central atom is in a position to decrease its oxidation number. Now, the maximum oxidation state or oxidation number of phosphorus (P) is `+5`. It cannot increase the same but at the sametime can decrease its oxidation number. In `PCl_(5)`, oxidation number of P is already `+5`. It therfore, cannot act as a reducing agent. However it can behave as an oxidising agent in certain reactions in which its oxidation number decreases. For example, `2Ag+overset(+5)PCl_(5) to 2AgCl+overset(+3)PCl_(3)` `Sn+2overset(+5)PCl_(5) to SnCl_(4)+2overset(+3)PCl_(3)` |
|
| 699. |
Ammonia gas can be collected by the downward displacement ofA. waterB. airC. mercuryD. acid |
|
Answer» Correct Answer - 2 Ammonia gas is prepared in the laboratory by heating ammonium chloride with slaked lime, `Ca(OH)_(2)`, in the ratio of `3:2`. The mixture is taken in a flask and the heated gently. The gas evolved is passed through lime tube and finally collected in a dry jar (because `NH_(3)` is highly soluble in `H_(2)O` by downward displacement of air (as `NH_(3)` is lighter than air). |
|
| 700. |
Noble gases used in diving apparatus and discharge tube is respectively (main use)A. `He,Ne`B. Ne, NeC. He, HeD. He, Ar |
| Answer» Correct Answer - A | |