94420 + Interview Questions in Chemistry in Class 12

1.	Metamerism is advance type of
Answer» OPTICAL isomerism geometrical isomerism CHAIN and POSITION isomerism only chain isomerism Answer :C

Discussion

2.	Metamerism is exhibited by__________.
Answer» hydrocarbon nitro COMPOUNDS MINERAL ACID ETHER ANSWER :D

Discussion

3.	Metals which will not evolve H_2 gas with dil. HCl are
Answer» CU, AG, Au Cu, Zn , Al Fe, Ag , Pt Hg , MG , Pt Answer :A

Discussion

4.	Metals which donot form amalgam ore :
Answer» FE NI Zn Au. Solution :Fe and Ni DONOT FORM AMALGAMS.

Discussion

5.	Metals which do not give flame test ?
Answer» Be Li Mg Ba Answer :A::C

Discussion

6.	Metals which do not form amalgam
Answer» FE Zn Ni Au Solution :Fe DONOT FORM AMALGUM

Discussion

7.	Metals which can be extracted by smelting process is/are
Answer» SN CU Zn Al Solution :Sn, Cu and Zn are the metals can be EXTRACTED by SMELTING process.

Discussion

8.	Metals those can be extracted with aqueous solution of sodium cyanide as complexes are
Answer» AU and Ag Fe and Ag Au and Hg Hg and Fe Answer :A

Discussion

9.	Metalsusuallydonotoccur in natureas nitrates. Why ?
Answer» Solution :Nitratesof allmetalsare SOLUBLE in water.Therefore,ifmetalnitrateswere PRESENTIN thecrustof earth,thesewouldbe slowlyandgraduallywashedbyrainwater intothe sea. It isbecauseof thisreasonthatmetalsusuallydo not occurin natureas NITRATES.

Discussion

10.	Metals which can be extracted by smelting process are
Answer» PB Fe Zn Al Answer :A::B::C

Discussion

11.	Metals which can be extracted by smelting process are:
Answer» PB Fe Zn Al Solution :The EXTRACTION of metal in its fused STATE or MOLTEN state is called smelting Pb, Fe, Z EXTRACTED by this.

Discussion

12.	Metalssulphideoccurmainly in rocksandmetal halidesinlakesandseas. Explain.
Answer» SOLUTION :METAL halidesbeingsolublein WATER, getdissolvedin rainwaterandarecarriedto lakesandseas duringweatheringofrocks. Ontheother HAND,metalsulphidesbeinginsolubleareleft behindin therocksasresidue.

Discussion

13.	Metals occur in the native form because of their
Answer» High Electronegativity Highreactivity LOW REACTIVITY Low DENSITY Answer :C

Discussion

14.	Metals obtained from sulphide ores are of least choice, because....
Answer» these ORES are COSTLY. reduction of these ores are DIFFICULT. SULPHUR dioxide gas evolved from them causes pollution. Both (B) and (C) Answer :D

Discussion

15.	Metals like platium and palladium can adsorb large voumes of hydrogen under special conditions. Such adsorbed hydrogen by the metal is know as
Answer» reactive hydrogen occluded hydrogen adsorbed hydrogen atomic hydrogen. Solution :ABSORPTION of hydrogen by PT and Pd is CALLED occlusion.

Discussion

16.	Metals likeCu, Ag, Zn,Hg andPb occurin natureassulphidesratherthan oxides ? Why ?
Answer» Solution :Thecationsof thesemetals, i.e.,` Cu ^( 2+ ), Zn ^(2 +), AG^( 2+)andHg^(2+)` (pseudo inertgas configuration,` (n- 1 ) s ^(2) g ^(6)d ^(10)) andPb^(2+) ` (inertpairconfiguration,`((n-1) s ^(2)p^( 6)d ^( 10)n s ^(2)) ` havehighpolarizingpowrandhencecan easilypolarize thebiggersulphideion thanthesmalleroxideion. Asaresult,sulphidesof thesemetalsareevenmorestablethan the OXIDESAND hencethese metals occurin NATUREIN formoftheirsulphidesratherthanoxides.

Discussion

17.	Metals like Cr and Al do not dissolve in concentrated nitric acid because of the formation of a__________ film of oxide on the surface.
Answer» SOLUTION :PASSIVE

Discussion

18.	Metals ions causing hardness of water are:
Answer» `Ca^(2+) and Na^+` `MG^(2+) and K^+` `Ca^(2+) and Mg^(2+)` `Zn^(2+) and Ba^(2+)` ANSWER :C

Discussion

19.	Metals having low melting point are refined by….
Answer» SOLUTION :LIQUATION.

Discussion

20.	Metals have conductivity of the order of (ohm^-1cm^-1):
Answer» `10^12` `10^5` `10^2` `10^-6` ANSWER :B

Discussion

21.	Metals have specific conductivity of the order of (ohm-1cm-1):
Answer» `10^12` `10^8` `10^2` `10^-6` ANSWER :B

Discussion

22.	Metals have few electrons in their valence shell while non-metals generally have more electrons in their valence shell. Metallic character is closely related to atomic radius and ionisation enthalpy. Metallic character increases from top to bottom in a group and decreases from let to right in a period of periodic table. metallic character is inversely related to electronegativity of element. Q. 3 N_0//2 atoms of X_((g))^(-) by energy E_(2). hence, ionisation potential and electron affinity of X_((g)) are: (N_(0)=Avogadro's number)
Answer» `(2E_(1))/(3N_(0)),(2E_(2))/(3N_(0))` `(2E_(1))/(3N_(0)),(3E_(2))/(2N_(0))` `(3E_(1))/(2N_(0)),(3E_(2))/(2N_(0))` `(3E_(1))/(2N_(0)),(2E_(2))/(3N_(0))` Answer :B

Discussion

23.	Metals have few electrons in their valence shell while non-metals generally have more electrons in their valence shell. Metallic character is closely related to atomic radius and ionisation enthalpy. Metallic character increases from top to bottom in a group and decreases from let to right in a period of periodic table. metallic character is inversely related to electronegativity of element. Q. The electronegativity of the following elements increase in the order:
Answer» <P>C, N, Si, P N, Si, C, P Si, P, C, N P, SI, N, C Answer :C

Discussion

24.	Considering the elements B, Al, Mg and K, the correct order of their metallic character is
Answer» `B GT AL gt MG gt K` `Al gt K gt B gt Mg` `Mg gt Al gt K gt B` `K gt Mg gt Al gt B` Answer :D

Discussion

25.	Metals have conductivity of the order of(ohm^(-1)M^(-1))
Answer» `10^(2)-10^(4)` `10^(4)-10^(7)` `10^(7)-10^(8)` `gt10^(8)` SOLUTION :METALS have conductivityof theordre of `10^(4)-10^(7)` oh `m^(-1)m^(-1)`

Discussion

26.	Metals have conductivity in the order of ("ohm"^(-1)" cm"^(-1))
Answer» `10^(12)` `10^(8)` `10^(2)` `10^(-6)` ANSWER :B

Discussion

27.	Metals constitute brass are
Answer» ZN and CU Cu and SN Cu and Sn EU, Zn and Sn Solution :Zn and Cu

Discussion

28.	Metals can be prevented from rusting by :
Answer» CONNECTING iror to more electropositive metal cathodic PROTECTION Connecting IRON to more electropositive metal anodic protection Connecting iron to LESS electropositive metal anodic protection Connecting iron to less electropositive metal cathodic protection Answer :A

Discussion

29.	Metals at the top of the electrochemical series are __________.
Answer» STRONG hydrating agents strong DEHYDRATING agents strong REDUCING agents strong OXIDISING agents Answer :D

Discussion

30.	"Metals are usually not found as nitrates in their ores . " Outof the following two (I and II) reasons which is/are true for the above observation ? I. Metal nitrates are highly unstable II. Metal nitrates are highly soluble in water
Answer» I is FALSE but II is TRUE I is true but II is false I and II are true I and II are false Answer :A

Discussion

31.	Metals are usually not found as nitrates in their ores. Out of the following two (I and II) reasons which is/ are true for the above observation ? I. Metal nitrates are highly unstable. II. Metal nitrates are highly soluble in water.
Answer» I is FALSE but II is TRUE. I is true but II is false I and II are true I and II are false Solution :It is false STATEMENT. (i) Metal nitrates are stable to heat. They decompose only when HEATED strongly. (ii) Metyal nitrates are highly soluble in water.

Discussion

32.	'Metals are usually not found as nitrates in their ores.'' Out of the following two (I and II) reasons which is / are true for the above observation ? (I) Metal nitrates are highly unstable (II) Metal nitrates are highly soluble in water
Answer» I is false but II is TRUE I and II are false I is true but II is false I and II are false Solution :NITRATES do not DECOMPOSE easily on heating and are HIGHLY soluble in water.

Discussion

33.	"Metalsareusuallynot foundas nitratesin theirores" Outofthefollowingtwo (I andII) reasonswhich is/aretruefortheaboveobservation ? I. Metal nitratesare highlyunstable. II. Metalnitratesarehighlysolublein water.
Answer» I is falsebutII ISTRUE I istrue but II is FALSE. I and II AREFALSE I andIIarefalse SOLUTION :All nitratesare watersolubleandarequitestable.

Discussion

34.	Metals are orderly collection of positive ions surrounded by and held together by a sea of free electrons. These electrons are mobile and are evenly spread out throughout the crystal. Each metal atom contributes one or more electrons towards this sea of mobile electrons. These free and mobile electrons are responsible for high electrical and thermal conductivity of metals. When an electric field is applied, these electrons flow through the network of positive ions. Similarly, when heat is supplied to one portion of a metal, the thermal energy is uniformly spread throughout by free electrons. Another important characteristic of metals is their lustre and colour in certain cases. This is also due to the presence of free electrons in them. Metals are highly malleable and ductile. 4. ''Metals are highly malleable and ductile.'' What are the applications of these properties ?
Answer» SOLUTION :We can beat the metal piece into a sheet that can be USED in various forms such as for SHELTER, doors, windows, utensils. We can draw wires from the piece of metal that find applications in jewellery, electrical and COMMUNICATION wires.

Discussion

35.	Metals are orderly collection of positive ions surrounded by and held together by a sea of free electrons. These electrons are mobile and are evenly spread out throughout the crystal. Each metal atom contributes one or more electrons towards this sea of mobile electrons. These free and mobile electrons are responsible for high electrical and thermal conductivity of metals. When an electric field is applied, these electrons flow through the network of positive ions. Similarly, when heat is supplied to one portion of a metal, the thermal energy is uniformly spread throughout by free electrons. Another important characteristic of metals is their lustre and colour in certain cases. This is also due to the presence of free electrons in them. Metals are highly malleable and ductile. How do you explain the electrical conductivity and thermal conductivity of metals ?
Answer» Solution :On passing electricity, the FREE ELECTRONS move from one end to the other end through the network of positive IONS. SIMILARLY, the free electrons carry the heat from one end to the other end.

Discussion

36.	Metals are orderly collection of positive ions surrounded by and held together by a sea of free electrons. These electrons are mobile and are evenly spread out throughout the crystal. Each metal atom contributes one or more electrons towards this sea of mobile electrons. These free and mobile electrons are responsible for high electrical and thermal conductivity of metals. When an electric field is applied, these electrons flow through the network of positive ions. Similarly, when heat is supplied to one portion of a metal, the thermal energy is uniformly spread throughout by free electrons. Another important characteristic of metals is their lustre and colour in certain cases. This is also due to the presence of free electrons in them. Metals are highly malleable and ductile. 1. Give the composition of metals.
Answer» Solution :METALS are orderly collection of positive ions SURROUNDED by and held together by a sea of ELECTRONS.

Discussion

37.	Metals are orderly collection of positive ions surrounded by and held together by a sea of free electrons. These electrons are mobile and are evenly spread out throughout the crystal. Each metal atom contributes one or more electrons towards this sea of mobile electrons. These free and mobile electrons are responsible for high electrical and thermal conductivity of metals. When an electric field is applied, these electrons flow through the network of positive ions. Similarly, when heat is supplied to one portion of a metal, the thermal energy is uniformly spread throughout by free electrons. Another important characteristic of metals is their lustre and colour in certain cases. This is also due to the presence of free electrons in them. Metals are highly malleable and ductile. 2. Where does the sea of electrons come from ?
Answer» Solution :Each METAL atom contributes ONE or more ELECTRONS to the SEA of electrons.

Discussion

38.	Metals are extracted from their ores by a wide variety of techniques. The most common ores are oxides. Most metals are obtained by direct treatment of theirs ores with chemical agents, but the extraction of certain others require electrolysis. An example of the former type of process is the extraction of iron from its oxide, described by the following equation : Fe_(2) O_(3) + 3C rarr 2Fe + 3CO The relative ease of extraction of a metal from its oxide can be estimated using the Ellingham diagram, as shown in the figure. The diagram plots the free energies of formation of various oxides per mole of consumed oxygen as a function of absolute temperature. Which of the following best explains why the free energy of formation of Fe_(2)O_(3) becomes less negative as the temperature is increased.
Answer» The free energy of FORMATION is independent of the absolute temperature. Entropy DROPS as a RESULT of the CONSUMPTION of oxygen. At low temperature, the free energy of formation becomes LESS dependent on the enthalpy of formation. As entropy increases, the free energy of formation increases. Answer :B

Discussion

39.	Metals are extracted from their ores by a wide variety of techniques. The most common ores are oxides. Most metals are obtained by direct treatment of theirs ores with chemical agents, but the extraction of certain others require electrolysis. An example of the former type of process is the extraction of iron from its oxide, described by the following equation : Fe_(2) O_(3) + 3C rarr 2Fe + 3CO The relative ease of extraction of a metal from its oxide can be estimated using the Ellingham diagram, as shown in the figure. The diagram plots the free energies of formation of various oxides per mole of consumed oxygen as a function of absolute temperature. FIITJEE_CHE_MB_04_C02_E07_009_Q01.png" width="80%"> When ferric oxide is reduced to obtain iron metal, CO_(2) or CO can be produced. The production of CO_(2)
Answer» is directily proportional to the temperature is inversely proportional to the temperature is independent of the temperature requires COOLING of the CO Answer :C

Discussion

40.	Metals are extracted from their ores by a wide variety of techniques. The most common ores are oxides. Most metals are obtained by direct treatment of theirs ores with chemical agents, but the extraction of certain others require electrolysis. An example of the former type of process is the extraction of iron from its oxide, described by the following equation : Fe_(2) O_(3) + 3C rarr 2Fe + 3CO The relative ease of extraction of a metal from its oxide can be estimated using the Ellingham diagram, as shown in the figure. The diagram plots the free energies of formation of various oxides per mole of consumed oxygen as a function of absolute temperature. All of the following reagents could be used to extract lead from its oxide except
Answer» MOLECULAR fluorine Molecular boron Molecular NITROGEN ELEMENTAL CARBON ANSWER :A

Discussion

41.	Metals are extracted from their ores. Among the following which metal is extracted from bauxite:Zinc,Iron,Aluminium,Copper
Answer» Zinc Iron Aluminium Copper Answer :B

Discussion

42.	Metallurgy is the process of :
Answer» gangue Roasting the ORE Extracting the METAL from the ore Adding CARBON to the ore in BLAST furnace Answer :C

Discussion

43.	(iv) Metallurgy is the process of :
Answer» CONCENTRATING the ore roasting the ore extracting the metal from the ore adding CARBON to the ore in blast furnace Answer :C

Discussion

44.	Metallrgical process can be explained in terms of thermodynamic principles. Reduction of Cr_2O_3 by Aluminium metal is accompained by negative DeltaG^@value and is thermodynamically feasible. Why does this reaction fail at room temperature?
Answer» Answer :The reactions is `Cr_2O_3+2Al rarr Al_2O_3 + 2Cr` for which `DeltaG^@` is negative. Certain amount of ACTIVATION ENERGY is required for this REACTION to take place. So HEATING is required and it does not take place at room temperature.

Discussion

45.	Metalloids are
Answer» alloys of ALKALI metals with other metals. colloids of metals element having some properties of both metals and non-metals . metals heavier than lead. SOLUTION :A metalloid is a chemical element with properties in between , or that are a mixture of , those of metals and non-metals . There is no standard DEFINITION of a metalloid, nor is there complete AGREEMENT as to which elements are appropriately classified as such. The six commonly recognised metalloids are BORON , silicon , germanium , arsenic , antimony and tellurium . Elements less commonly recognised as metalloids include carbon , aluminium , selenium , polonium and astatine.

Discussion

46.	Metallic tin in the presence of HCl is oxidised by K_(2)Cr_(2)O_(7) to stannic chloride. What volume of decinormal dichromate solution would be reduced by 1 g of tin
Answer» 168.9 ml 175.49 ml 170.50 ml 162.38 ml Solution :`0.1xxV=(2)/(119)` `V=168.06ml`

Discussion

47.	Metalloid among the following is:
Answer» O S Te Po Answer :C

Discussion

48.	Metalloid among the following is :
Answer» Si C Ge Pb Answer :C

Discussion

49.	Metallic sodium cannot be prepared from electrolysis of an aqueous solution of NaCl because the SRPH_(2)OltSRPNa^(+)
Answer» SOLUTION :SRP `H_(2)OgtSRPNa^(+)` so `H_(2)O` will be REDUCED in preference to `Na^(+)` ion.

Discussion

50.	Metallic sodium is extracted by the electrolysis of brine (eq. NaCl) .After electrolysis the electrolytic solution becomes basic in nature.Write the possible electrode reactions.
Answer» SOLUTION :Brine is a solution chloride (molten state). The process of electrolysis involves using an electric current to bring about a chemical change and MAKE new chemicals.In the electrolysis of brine ,sodium ions migrate to the cathode ,where ELECTRONS ENTERS the melt and are reduced to sodium metal . `Na^(+)e^(-)toNa(at cathode)` Chloride ions migrate the other way toward the anode.They give up thier electrons to the anode and are oxidised to chlorine gas. `Cl^(-)to(1)/(2)Cl_(2)+e^(-)`(at anode) Overall reaction:` 2NaCl to 2Na(s)+Cl_(2)(g)` For aqueous solution of NaCl:`H_(2)O+2e^(-) to H_(2)uarr+2OH^(-)` (at cathode) `Cl^(-) to (1)/(2)Cl_(2)+e^(-)`(at anode) Overall reaction: `NaCl(aq)+H_(2)O to Na^(+)(aq)+OH^(-)(aq)+H_(2)(g)+(1)/(2)Cl_(2)(g)` After electrolysis the electrolytic becomes basic in nature.[Due to FORMATION of hydroxide `(OH^(-))` ion].

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Metamerism is advance type of

Metamerism is exhibited by__________.

Metals which will not evolve H_2 gas with dil. HCl are

Metals which donot form amalgam ore :

Metals which do not give flame test ?

Metals which do not form amalgam

Metals which can be extracted by smelting process is/are

Metals those can be extracted with aqueous solution of sodium cyanide as complexes are

Metalsusuallydonotoccur in natureas nitrates. Why ?

Metals which can be extracted by smelting process are

Metals which can be extracted by smelting process are:

Metalssulphideoccurmainly in rocksandmetal halidesinlakesandseas. Explain.

Metals occur in the native form because of their

Metals obtained from sulphide ores are of least choice, because....

Metals like platium and palladium can adsorb large voumes of hydrogen under special conditions. Such adsorbed hydrogen by the metal is know as

Metals likeCu, Ag, Zn,Hg andPb occurin natureassulphidesratherthan oxides ? Why ?

Metals like Cr and Al do not dissolve in concentrated nitric acid because of the formation of a__________ film of oxide on the surface.

Metals ions causing hardness of water are:

Metals having low melting point are refined by….

Metals have conductivity of the order of (ohm^-1cm^-1):

Metals have specific conductivity of the order of (ohm-1cm-1):

Considering the elements B, Al, Mg and K, the correct order of their metallic character is

Metals have conductivity of the order of(ohm^(-1)M^(-1))

Metals have conductivity in the order of ("ohm"^(-1)" cm"^(-1))

Metals constitute brass are

Metals can be prevented from rusting by :

Metals at the top of the electrochemical series are __________.

"Metals are usually not found as nitrates in their ores . " Outof the following two (I and II) reasons which is/are true for the above observation ? I. Metal nitrates are highly unstable II. Metal nitrates are highly soluble in water

Metals are usually not found as nitrates in their ores. Out of the following two (I and II) reasons which is/ are true for the above observation ? I. Metal nitrates are highly unstable. II. Metal nitrates are highly soluble in water.

'Metals are usually not found as nitrates in their ores.'' Out of the following two (I and II) reasons which is / are true for the above observation ? (I) Metal nitrates are highly unstable (II) Metal nitrates are highly soluble in water

"Metalsareusuallynot foundas nitratesin theirores" Outofthefollowingtwo (I andII) reasonswhich is/aretruefortheaboveobservation ? I. Metal nitratesare highlyunstable. II. Metalnitratesarehighlysolublein water.

Metals are extracted from their ores. Among the following which metal is extracted from bauxite:Zinc,Iron,Aluminium,Copper

Metallurgy is the process of :

(iv) Metallurgy is the process of :

Metallrgical process can be explained in terms of thermodynamic principles. Reduction of Cr_2O_3 by Aluminium metal is accompained by negative DeltaG^@value and is thermodynamically feasible. Why does this reaction fail at room temperature?

Metalloids are

Metallic tin in the presence of HCl is oxidised by K_(2)Cr_(2)O_(7) to stannic chloride. What volume of decinormal dichromate solution would be reduced by 1 g of tin

Metalloid among the following is:

Metalloid among the following is :

Metallic sodium cannot be prepared from electrolysis of an aqueous solution of NaCl because the SRPH_(2)OltSRPNa^(+)

Metallic sodium is extracted by the electrolysis of brine (eq. NaCl) .After electrolysis the electrolytic solution becomes basic in nature.Write the possible electrode reactions.