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.
| 701. |
Sulphur trioxide can be obtained by which of the following reactions:A. `CaSO_(4)+C overset(Delta)rarr`B. `Fe_(2)(SO_(4))_(3) overset(Delta)(rarr)`C. `S+H_(2)SO_(4) overset(Delta)rarr`D. `H_(2)SO_(4)+PCl_(5)rarr` |
|
Answer» Correct Answer - 2 Heating ferric sulphate strongly `Fe_(2)(SO_(4))_(3) overset(Delta)(rarr) Fe_(2)O_(3)+SO_(3)` Other reactions are `2CaSO_(4)+C overset(Delta)(rarr) 2CaO+2SO_(2)+CO_(2)` `S+H_(2)SO_(4) overset(Delta)(rarr) 2H_(2)O+SO_(2)` `H_(2)SO_(4)+PCl_(5) rarr HO-SO_(2)-Cl+POCl_(3)+HCl` `HO-SO_(2)-Cl overset(PCl_(5))(rarr) Cl-SO_(2)-Cl +POCl_(3)+HCl` |
|
| 702. |
(a) Write the balanced chemical equation for the reaction of `Cl_(2)` with hot and concentrated `NaOH`. Is this reaction a disproportion reaction? (b) when `HCl` reacts with finely powdered iron, it forms ferrous chloride and not ferric chloride. why? Deduce the molecular shape of `BrF_(3)` on the basis of `VSEPR` theory. |
|
Answer» `3Cl_(2) + 6NaOH to 5NaCl + NaClO_(3) + 3H_(2) O` Yes, chlorine from zero oxidation state is changed to `–1` and `+5` oxidation states. |
|
| 703. |
Oxides formed by `p`-block elements may be `(i)` basic `(ii)` acidic `(iii)` amphoteric `(iv)` neutral |
| Answer» (c) Borax is a salt of a strong base (NaOH) and a weak acid `(H_(3)BO_(3))`. It is, therefore, basic in nature. | |
| 704. |
Which of the following elements from amphoteric oxides?A. `N` and `P`B. `P` and `As`C. `As` and `Sb`D. `Sb` and `Bi` |
|
Answer» Correct Answer - 3 Group `15` shows the usual trend, that metallic character increases in decending the group. Thus first two elements `N` and `P`, are nonmetal,`As` and `Sb` are metallodis,Which show metallic as well as nonmetallic properties and `Bi` is a true metal. The increaseing metallic character is shown by the following features. A. In the appearence and structures of the elements: nitrogen is a colourless gas ,phosphorus is a white, Waxy solid while rest of the elements are brittle ,metallic solids. B. By their tendency to form positive ions:only antimony and bismuth can from the `3-`valent cation`E^(3+).` C. By the nature of their oxides: nonmetallic oxides are acidic, metallodic oxides are amphoteric and metallic oxides are typically basic. Thsu the normal oxide of `N` and `P(N_(2)O_(3),P_(4)O_(6))`are stongly acidic, whereas those of `As` and `Sb(As_(4)O_(6), Sb_(4)O_(6))` are amphoteric and that of `Bi(Bi_(2)O_(3))` is largly basic. Antimony (III) oxide, being amphoteric dissolves in sodium hydroxide solution to form an antimontie (III) and in concentrated sulphuric acid to give a sulphate: `Sb_(4)O_(6)(s)+4OH^(-)(aq. )rarr4SbO_(2)^(-)(aq.)+2H_(2)O(l)` `Sb_(4)O_(6)(s)+6H_(2)SO_(4)(l)rarr4Sb_(2)(SO_(4))_(3)(a.q)+6H_(2)O(l)` D.The electrical resistivity of a metallic forms `(alpha-As 33, alpha-Sb 39` and `alpha-Bi 106 mu` ohm cm) are much lower than for white`P(1xx10^(17)mu" ohm cm")`, indicating an increase in metallic properties. However, the resistivity values are higher than the values for a good conductor such as `Cu, 1.67 mu" ohm cm")` and higher than,`Sn, 11`, and `Pb, 20 mu` ohm cm, in the adjancent group. |
|
| 705. |
Which of the following are amphoteric oxides?A. `CO_(2)` and `SiO_(2)`B. `SiO_(2)` and `GeO_(2)`C. `GeO_(2)` and `SnO_(2)`D. `SnO_(2)` and `PbO_(2)` |
|
Answer» Correct Answer - D `SnO_(2)` and `PbO_(2)` dissolve in concentrated alkalis giving stannates and plumbates: `SnO_(2) + 2NaOH rarr Na_(2)SnO_(3) + H_(2)O` `PbO_(2) + 2NaOH rarr Na_(2)PbO_(3) + H_(2)O` Both are insoluble in acids except when a complexing agent such as `F^(-)` or `Cl^(-)` is present. |
|
| 706. |
Which of the following oxides are amphoteric?A. `CO`B. `SnO_(2)`C. `ZnO`D. `BeO` |
| Answer» Correct Answer - B::C::D | |
| 707. |
Which of the following is an industrial fuel?A. Water gasB. Producer gasC. Coal gasD. All of these |
|
Answer» Correct Answer - D They all consist of `CO` which is an important fuel because it evolves a considerable amount of heat when it burns in air: `2CO + O_(2) rarr 2CO_(2), Delta_(C)H^(@) = -565 kJ mol^(-1)` Water gas is a particularly good fuel, i.e., it has high calorific value, because both `CO` and `H_(2)` burn and evolve heat. Producer gas is a less efficient fuel than water gas (i.e., it has a lower calorific value) as only part of the gas will burn. |
|
| 708. |
Which of the following compounds give ammonia with water?A. `Mg_(3)N_(2)`B. `AlN`C. `CaCN_(2)`D. `Ca(CN)_(2)` |
| Answer» Correct Answer - A::B::C | |
| 709. |
Nitric acid can be obtained from ammonia via the formation of intermediate compoundsA. Nitric oxide and nitrogen dioxideB. Nitrogen and nitric oxideC. Nitric oxide and dinitrogen pentoxideD. Nitrogen and nitrous oxide |
|
Answer» Correct Answer - A Nitric oxide (NO) and nitrogen dioxide `(NO_(2))` in the ostwald process. |
|
| 710. |
Which of the following compounds is mixed with `N_(2)O_(4)` to serve as a rocket fuel?A. `NH_(2)OH`B. `NH_(3)`C. `N_(2)H_(4)`D. `N_(3)H` |
|
Answer» Correct Answer - 3 The methyl derivatives of hydrazine `MeNHNH_(2)` and `Me_(2)N NH_(2)` are mixed with `N_(2)O_(4)` and used as a rocket fuel in the space shuttle, in guided missiles,and (earlier)in the Apollo lunar modules. |
|
| 711. |
Which of the following compounds will not give ammonia on heating?A. `(NH_(4))_(2)SO_(4)`B. `NH_(2)CONH_(2)`C. `NH_(4)NO_(2)`D. `NH_(4)Cl` |
|
Answer» Correct Answer - C `NH_(4)NO_(2(aq))overset("heat")rarrN_(2(g))+2H_(2)O_((l))` |
|
| 712. |
Fill in the blanks : (i) `Ca_(3)P_(2)+6HClrarr 3CaCl_(2) + ....p ....` (ii) `P_(4) + 3NaOH + 3H_(2)O rarr ...q...+3 NaH_(2)PO_(2)` (iii) `PH_(4)I + KOH rarr KI + H_(2)O+...r...` p, q and r respectively areA. `PH_(3), H_(3)PO_(3), Pl_(3)`B. `PH_(3), PH_(3), PH_(3)`C. `PCl_(3), H_(3)PO_(4),PH_(3)`D. `PCl_(5), PH_(3), P_(4)O_(6)` |
| Answer» Correct Answer - B | |
| 713. |
How boron isotope controls nuclear reaction? |
| Answer» `._(5)B^(10)+._(0)n^(1)to._(5)B^(11)` | |
| 714. |
Assertion (A) : Silicones are water repelling in nature Reason (R) : Silicones are organosilicon polymers, which have `(-R_(2)SiO-)` as repeating unit.A. A and R both are correct R is the correct explanation of AB. Both A and R are correct but R is not the correct explanation of AC. A and R both are correctD. A is not correct but R is correct |
|
Answer» Correct Answer - b Silicones are a groups of organo silicon polymers which have `(R_(2)SiO)` as a repeating unit. This suggests that silicones are surrounded by non-polar alkyl groups that are water repelling in nature. They have wide applications. It is used for water proofing of fabrics. |
|
| 715. |
Assertion : Ozone layer in the upper region of atmosphere protects earth from UV radiations of sun. Reason : Ozone is a powerful oxidising agent as compared to oxygen.A. If both assertion and reason are true and reason is the correct explanation of assertion.B. If both assertion and reason are true but reason is not the correct explanation of assertion.C. If assertion is true but reason is false.D. If both assertion and reason are false. |
| Answer» Correct Answer - B | |
| 716. |
Assertion : `O_(3)` acts as a powerful oxidising agent. Reason : `O_(3)` oxidises lead sulphide to lead sulphate and iodide ions to iodine.A. If both assertion and reason are true and reason is the correct explanation of assertion.B. If both assertion and reason are true but reason is not the correct explanation of assertion.C. If assertion is true but reason is false.D. If both assertion and reason are false. |
|
Answer» Correct Answer - B Ozone acts as powerful oxidising agent because it liberates atoms of nascent oxygen. `(O_(3) rarr O_(2) + O)` |
|
| 717. |
Addition of `Cl_(2) to KI solution give its a brown colour but excess of cl_(2) ` turns it colourless. Why? |
|
Answer» The initial brown colour is due to relase of `I_(2)` from the solution. But excess of chlorine dissolves iodine to form a colourless compound iodic acid. `Cl_(2)+2KI to 2KCl+ underset(("Brown"))(I_(2))` `5Cl_(2)+I_(2)+6H_(2)O to 10 HCl + underset(("Colourless"))(2HIO_(3))` |
|
| 718. |
Pure nitric acid on is a colourless liquid, but on exposure to sunlight it turns slightly brown, due toA. the formation of `H_(3)O^(+)` and `NO_(3)^(+)`B. the formation of `N_(2)O`C. slight decomposition into `NO_(2)` and `O_(2)`D. slight decomposition into `N_(2)O` and `O_(2)` |
|
Answer» Correct Answer - 3 Concentrated nitric acid decomposes photochemically and gradually assumes a yellow colour due to the presence of dissolved nitrogen dioxide: `4HNO_(3)(aq.)rarr4NO_(2) (aq)+ 2H_(2)O (l)+O_(2)(g)` The same reaction occurs but at a much faster rate, when the acid is heated. |
|
| 719. |
A solution of `KBr` is treated with each of the following which one would liberate bromine?A. Sulphur dioxideB. IodineC. ChlorineD. Hydrogen iodide |
|
Answer» Correct Answer - 3 Chlorine is the strongest oxidixing agent of the given substances: `2KBr+Cl_(2)rarr2KCl+Br_(2)` |
|
| 720. |
Which of the following is not correct for carbon monoxide ?A. It is a colorless gas.B. It is an odorless gas.C. It is highly soluble in water.D. It is a neutral oxide. |
|
Answer» Correct Answer - C It is only slightly soluble in water. |
|
| 721. |
Carbon monoxide on heating with `NaOH` at `200^(@) C` under `6-10 atm` pressure yields.A. sodium formateB. sodium acetateC. sodium oxalateD. sodium carbonate |
|
Answer» Correct Answer - A Although `CO` is not a true acid anhydride since it does not react with to produce an acid, it reacts under pressure with fused sodium hydroxide to give sodium formate (methanoate): `NaOH(l) + CO(g) rarr HCOONa(s)` Formic acid (methanoic acid) is produced from the sodium salt by the addition of dilute hydrochloric acid. |
|
| 722. |
Hydrogen sulphide cannot be dried by passing through conc. `H_(2)SO_(4)` . Why ? |
|
Answer» Hydrogen sulphide cannot be dried by passing through conc. `H_(2)SO_(4)` since chemical reaction takes place. `H_(2)SO_(4) +H_(2)S to 2H_(2)O+SO_(2)+S` |
|
| 723. |
Which is not a method of preparing carbon monoxide on a commercial scale?A. `C_(S) + H_(2) O_((g)) overset(473 - 1273 K)(to) CO_((g)) + H_(2(g))`B. `2C_((s)) + O_(2(g)) + 4N_(2(g)) overset(1273 K)(to) 2CO_((g)) + 4N_(2(g))`C. `2C_((s)) + O_(2(g)) overset(Delta)(to) 2CO_((g))`D. `HCOOH underset(conc.H_(2)SO_(4))overset(373 K)(to) H_(2)O + CO` |
|
Answer» Correct Answer - D HCOOH on dehydration gives CO. This method is used for producing CO at small scale. |
|
| 724. |
Which of the following is not formed when`N_(2)H_(4)` reacts with `H_(2)SO_(4)` to produce a series fasts?A. `N_(2)H_(4).H_(2)SO_(4)`B. `N_(2)H_(6)^(2+)`C. `N_(2)H_(4)^(2+)`D. `N_(2)H_(5)^(+)` |
|
Answer» Correct Answer - 3 `N_(2)H_(4)` is weak base. It reacts with acids to form two series of salts. The salts are white ionic crystalline solids and are soluble in water. `N_(2)H_(4)+HXrarrN_(2)H_(5)^(+)+X^(-)` `N_(2)H_(4)+2HXrarrN_(2)H_(6)^(2+)+2X^(-)` Solution of hydrazine is usually concentrated either by distilation or by adding `H_(2)SO_(4)` to precipitate the salt hydrazine sulphate `N_(2)H_(4).H_(2)SO_(4)`. |
|
| 725. |
Assertion : Diamond is the hardest substance on the earth. Reason : It has melting point. |
|
Answer» Correct Answer - B Diamond has a three dimensional network involving strong C - C bonds which are very difficult to break and hence, it is the hardest substance found on the earth and has high melting point. |
|
| 726. |
(a)Why are the elements of group `18` known as noble gases? (b)Noble gases have very low boiling points why? (c ) Does the hydrolysis of `XeF_(6)` lend in a redox reaction? |
| Answer» The elements present in Group 18 have their valence shell orbitals completely filled and, therefore, react with a few elements only under certain conditions. Therefore, they are now known as noble gases. | |
| 727. |
Why do noble gases have low boiling points ? |
| Answer» Noble gases being monoatomic haveweak dispersion forces and therefore liquefied at very low temperature. | |
| 728. |
give one method of preparation of `Na_(2)B_(4)O_(7)` |
| Answer» `4H_(3)BO_(3)+Na_(2)CO_(3) to Na_(2) B_(4)O_(7)+6H_(2)O+CO_(2)` | |
| 729. |
Give chemical composition of glassy bead. |
| Answer» `NaBO_(2)+B_(2)O_(3)` | |
| 730. |
On moving down the group, the basic nature of hydroxide of boron family.A. DecreasesB. IncreasesC. First decreases then increasesD. Remains same |
| Answer» Correct Answer - B | |
| 731. |
Give hydrolysis product of trihalides of boron family. |
| Answer» `[M(OH)_(4)]^(-) and [M(H_(2)O)_(6)]^(3+)` | |
| 732. |
Possible oxidation states of boron family elements are : |
| Answer» Group oxidation state of boron family is +3. | |
| 733. |
Give oxidation state of all boron atom in borax. |
| Answer» Correct Answer - `+3` | |
| 734. |
The most stable oxidation state of boron isA. `+3`B. `+1`C. `-3`D. `-1` |
|
Answer» Correct Answer - A In the combined state, boron is always trivalent and exhibits oxidation number `+3`. |
|
| 735. |
Which of the following group `13` elements has the highest density?A. `Al`B. `Ga`C. `In`D. `Tl` |
|
Answer» Correct Answer - D The density of group `13` elements increases regularly down the group from `B` to `Ti`. However the densities of `B` and `Al` are quite lower than those of other elements. |
|
| 736. |
Which of the following has the highest boiling point?A. `Si`B. `Ge`C. `Sn`D. `Pb` |
|
Answer» Correct Answer - A The overall order of boiling point is `Si gt Ge gt Sn gt Pb` Note that the element `C` sublimes at its melting point `(4100^(@)C)`. |
|
| 737. |
Which of the following is a useful material for measuring high temperatures?A. `Al`B. `Ga`C. `In`D. `Tl` |
|
Answer» Correct Answer - B Because it provides the maximum difference between its melting point `(30^(@)C)` and boiling point `(2403^(@)C)`. |
|
| 738. |
Which of the following is correct regarding the values of ionization enthalpies?A. `B` has lower ionization enthalpy than `Be`.B. `Al` has lower ionization enthalpy than `Mg`.C. `Ga` has lower ionization enthalpy than `Ca`.D. All of these. |
|
Answer» Correct Answer - D Due to the removal of `p` electron from the same shell. |
|
| 739. |
Which of the following has the highest boiling point?A. `B`B. `Al`C. `Ga`D. `In` |
|
Answer» Correct Answer - A Boiling points of group `13` elements follow a regular trend and decrease regularly on moving down the group. |
|
| 740. |
Which of the following is incorrect about group `13` elements?A. They are less electropositive (or metallic) as compared to `s`-block elements.B. On moving down the group, the electropositive character increases.C. The standard reduction electrode potentials `E^(@) (M^(3+)//M)` become less negative from `Al` to `Ga` to `In` and the potential becomes positive for `Tl`.D. None of these. |
|
Answer» Correct Answer - B The electropositive (or metallic) nature of group `13` elements increases from `B` to `Al`, but then decreases from `Al` to `Tl`. The increase in metallic character from `B` to `Al` is the usual trend on descending a group and is associated with the increase of atomic size leading to the decrease of ionization enthalpy. However, `Ga, In`, and `Tl` do not continue the trend. These elements exhibit decreasing tendency to lose electrons because of the poor shielding of valence electrons by the `d`- and `f`-electrons present in the inner shells of these elements. |
|
| 741. |
Which of the following has the highest melting point?A. `Tl`B. `In`C. `Ga`D. `Al` |
|
Answer» Correct Answer - D The overall order is `B gt Al gt Tl gt In gt Ga` Thus, `B` has the highest melting point while `Ga` has the lowest melting point. |
|
| 742. |
What is the oxidation state of Cl in `HClO_(4)` ? |
| Answer» `overset(+1)(HCl)overset(-2)(O_(4))(+7)` | |
| 743. |
The conjugate base of `HClO_(4)` is a weaker base than `H_(2)O`. Explain. |
|
Answer» It is explained on the basis of Bronsted-Lowry concept. `{:(HClO_(4), +" "H_(2)O " "harr, ClO_(4)^(-), +" " H_(3)O^(+)),("Acid-I"," ""Base-I","Base-I"," ""Acid-II"),("Strong"," ""Strong","Weak"," ""Strong"):}` Please note that a strong acid has a weak conjugate base and a strong base has a weak conjugate acid. |
|
| 744. |
Write balanced chemical equation for the following : (a) NaCl is heated with sulphuric acid in the presence of `MnO_(2)` (b) Iodine is treated with Conc. `HNO_(3)`. |
|
Answer» (a) `2NaCl+MnO_(2)+3H_(2)SO_(4) to 2NaHSO_(4) +MnSO_(4) +Cl_(2) +2H_(2)O` (b) `I_(2) +10HNO_(3) to 2HIO_(3) +10NO_(2) +4H_(2)O`. |
|
| 745. |
Boron halides behave as Lewis acid because of their ___ nature.A. Ionisation propertyB. Electron deficient natureC. Acidic natureD. Covalent nature |
| Answer» Correct Answer - B | |
| 746. |
The decreasing order of power of boron halides to act as Lewis acids isA. `BF_(3) gt BCI_(3) gt BBr_(3)`B. `BBr_(3) gt BCI_(3) gt BF_(3)`C. `BCI_(3) gt BF_(3) gt BBr_(3)`D. `BCI_(3) gt BBr_(3) gt BF_(3)` |
| Answer» Correct Answer - B | |
| 747. |
Hallides of boron and aluminium are Lewis Acids. Assign reason.A. Both halides `(MX_(3))` can accept electrons from a donor to complete their octet.B. Both halides `(MX_(3))` can donate a pair of electronsC. Both halides `(MX_(3))` are covalent polymeric structures.D. Both halides `(MX_(3))` react with water to give hydroxides and HCI |
|
Answer» Correct Answer - A Both boron and aluminium in their trihalides `(MX_(3))` possess six electrons in their valence shell. To complete the octet they can accept a lone pair of electrons acting as Lewis acids. |
|
| 748. |
Allotropes of carbon: There are three forms of carbon. i.e., diamond, graphite and fullerene which exxist in crystalline form. Graphite and diamond occur in nature. The structure of diamond is tetrahedral with `sp^(3)` hybridisation and diamond exist in 3-D netowrk solid. in graphite, carbon is `sp^(2)` hybridised. each carbon linked to other carbon linked to other carbon atom forms hexagonal ring. it has a layered structure. diamond and graphite are purest form of carbon. Fullerene constitute a new family of carbon allotropes. Consisting of large spheroidal molecule of compound with general formula `C_(2n)`. common fullerene `C_(6),C_(70)`, contain 5 and 6 membered rings. Q. Which of the following statement is incorrect for graphite?A. Very small, the layers being tightly packedB. Many times larger than the covalent radius of carbonC. More than twice the covalent radius of carbonD. The same as the covalent radius of carbon |
| Answer» Correct Answer - C | |
| 749. |
Allotropes of carbon: There are three forms of carbon. i.e., diamond, graphite and fullerene which exxist in crystalline form. Graphite and diamond occur in nature. The structure of diamond is tetrahedral with `sp^(3)` hybridisation and diamond exist in 3-D netowrk solid. in graphite, carbon is `sp^(2)` hybridised. each carbon linked to other carbon linked to other carbon atom forms hexagonal ring. it has a layered structure. diamond and graphite are purest form of carbon. Fullerene constitute a new family of carbon allotropes. Consisting of large spheroidal molecule of compound with general formula `C_(2n)`. common fullerene `C_(6),C_(70)`, contain 5 and 6 membered rings. Q. Which of the following statement is correct regarding `C_(60)` fullerene?A. It contains 20, six membered ring and 12, five membered ringsB. It contains 20, six membered ring and 12, five membered ringsC. It consist of 25, six membered and 12, five membered ringsD. It consists of 12, six membered and 25, five membered rings. |
| Answer» Correct Answer - B | |
| 750. |
which of the following is not true about structure of diamond and graphite?A. In diamond, each carbon is `sp^(3)` hybridised while in graphite each carbon is `sp^(2)` hybridesed.B. In diamond, carbon atoms are closely packed in crystal lattice while grahite has layer structureC. Diamond is a hard substance while graphite is a soft substanceD. Graphite is thermodynamically vary less stable as compared to diamond and is amorphous form of carbon. |
| Answer» Correct Answer - D | |