52671 + Interview Questions in Chemistry in Class 11

1.	Magnesium burns with a _____ flame.
Answer» SOLUTION :`MGO and Mg_3N_2`

Discussion

2.	Magnesium on heating separately with aqueousferric chloride and ammonium chloride gives the same gas, X,X is inflammable and reacts with metal to form electrovalent soild ,which on hydrolysis gives the same gas .Predict the gas X.
Answer» Solution :The gas .X. is hydrogen .Magnesium liberates hydrogen on reaction with aqueous ferric chloride `3Mg +2FeCl_(3)+6H_(2)O to 2MgCl_(2)+2Fe(OH)_(3)+3H_(2)` `MG+2NH_(4)CL to MgCl_(2)+2NH_(3)+H_(2)` The ELECTROVALENT solid is magnesium hydride , which gives hydrgen on hydrolysis . `Mg+H_(2) to MgH_(2)` `gH_(2+2H_(2)O to Mg(OH)_(2)+2H_(2)`

Discussion

3.	Magnesium metals burns in air to give a white ash . When this ash is treated with water , the odour of ammonia can be detected . Explain .
Answer» Solution :Mg burns in air to form MGO and `Mg_(3) N_(2)`. `2 Mg + O_(2) overset(Delta) (to) 2 MgO , 3 Mg+ N_(2) overset(Delta)(to) Mg_(3) N_(2)` Magnesium nitride on HYDROLYSIS with `H_(2)O` (moisture) GIVES `NH_(3)` . `Mg_(3)N_(2) + 6 H_(2)O to 3 Mg (OH)_(2) + 2 NH_(3)`

Discussion

4.	Magnesium loses electrons successively to form Mg^(+),Mg^(2+)andMg^(3+) ions . Which step will have the highest ionisation energy and why ?
Answer» Solution :`UNDERSET("NEUTRAL atom")(Mg)(g) to Mg^(+) +e(I.E_(1) = X_(1))` `(Dbt: e or e^(-))` `underset("Unipositive cation")(Mg^+)to Mg^(2+) +e^(-)(I.E_(2) -X_(2))` `underset("Dipositive cation")(Mg^2+)to Mg^(3+)+e^(-)(I.E_(3) -X_(3))` (i) The third step will have the highest ionization energy. `I.E_3 gtI.E_2 gt I.E_1`. Because from a neutral gaseous atom, the electron removal is easy and less amount of energy is required. But from a dipositive cation, there will be more number of PROTONS than the electrons and there is more forces of ATTRACTION between the nucleus and electron. So the removal of electron in a dipositive cation, becomes highly difficult and more energy is required.

Discussion

5.	Magnesium may be called a refactory because it
Answer» has HIGH melting POINT Is a good condu ctor is CHEMICALLY inert as electrical insulator all the above Answer :4

Discussion

6.	Magnesium is a valuable, light weight used as a structural mataerial as well as in a alloys batteriesand in chemical synthesis. Although magnesium is plentiful in earth.s crust, it is mainly found in sea water (after sodium). There about 1.3 g of magnesium in every kilogram of sea water. The process for obtaining magnesium from sea water employs all three types of reactions, i.e. precipitation acid-base and redox reactions Preipitation reaction involves formation of
Answer» insouble `MgCO_(3)` by adding `Na_(2)CO_(3)` insouble `MG(OH)_(2)` by adding `Ca(OH)_(2)` insouble in `MgSO_(4)` by adding `Na_(2)SO_(4)` insouble `MgCI_(2)` By adding NaCI Solution :By the addition of `Ca(OH)_(2)` which is strong base to `Mg(OH)_(2) , its IONIC proiduct (Kip) INCREASES than the solubility product (Ksp) and precipitation takes place

Discussion

7.	Magnesium is a valuable, light weight metal used as a structural material as well as in alloy hatteries and in chemical s . Although magnesium is plentiful in Earth s maire found in the sea water after sodium). There is about 1.3 8 of magnesium in every kilogram of se water. The process for obtaining magnesium from en water employs all three types of reaction Le precipitation, acid-base, and redox reactions Redox reaction takes place in the extraction of Mg :
Answer» In the electronlytic cell when FUSED `MgCI_(2)` is subjected to electrolysis When fused `MgCO_(3)` is heated When fused `MgCO_(2)` is strongly heated Both (b) and (c ) Solution :When fused `MgCI_(2)` undergoes electolysis, reactions takes place at anode and cathode are At anode : (OXIDATION) : `2CI^(-) rarr CI_(2(g))+2e^(-)` At Cathode (REDUCTION): `Mg^(+2) +2e^(-) rarr Mg_((s))`

Discussion

8.	Magnesium is a valuable, light weight metal used as a structural material as well as in all batteries and in chemical synthesis. Although magnesium is plentiful in carth crust, it is ma found in the sea water after sedium. There is about 1.38 of magnesium in every kilogram of water. The process for obtaining magnesium from se water employs all three types of reach le... precipitation acid-hase and redor racions. Acid-base reaction involves reaction between.
Answer» `MgCO_(2) and HCI` `MG(OH)_(2) and H_(2)SO_(4)` `Mg(OH)_(2) and HCI` `MgCO_(3) and NaCI` Solution :`Mg(OH)_(2)+2HCIrarrMgCI_(2)+2H_(2)O`

Discussion

9.	Soaps do not work in hard water containing calcium and magnesium ions because
Answer» SOLUTION :373 K, COLD

Discussion

10.	Magnesium content present in aqueous solution can be precipitated using either aqueous sodium carbonate or aqueous barium hydroxide .Write equation and discuss.
Answer» Solution :`Mg^(2+)+Na_(2)CO_(3) to MgCO_(3) darr +2NA^(+)` Sodium carbonate is water soluble but magnesium carbonate is almost insoluble in water `Mg^(2+)+BA(OH)_(2)toMg(OH)_(2) uarr +Ba^(2+)` Barium hydroxide is water soluble , but magnesium hydroxide is almost insolublein water .

Discussion

11.	Magnesium chloride is an ionic substance. It is also volatile. It does not impart flame colour. Why?
Answer» Solution :Magnesiumhas small sizeand moreexcitationenergy . The energy absorbedin the flameis more . The EXCITED ELECTRONS transmitback to the original state with the emissionof energy. The EMISSION is in the HIGH energy ultra violet region .

Discussion

12.	Magnesium burns in the atmosphere of the following gases ?
Answer» `CO_(2)` `N_(2)O` `N_(2)` `SO_(2)` SOLUTION :MG combines with `N_(2)` to form `Mg_(3)N_(2)` while it decomposes all OTHERS to GET oxygen to form MgO.

Discussion

13.	Magnesium burns in air forming …….and ……. .
Answer» SOLUTION :`MGO` and `Mg_(3)N_(2)`

Discussion

14.	Write the equations for the following and balance them Magnesium reacts with nitrogen to give magnesium nitride.
Answer» `N_2` `CO` `NO_2` NONE of these SOLUTION :`N_2`

Discussion

15.	Magnesite is a mineral of
Answer» Be MG Sr Ba Solution :MAGNESITE `(MgCO_(3))` is the MINERAL of Mg.

Discussion

16.	Magnesia is a refractory material.Explain.
Answer» Solution :Magnesia,MGO is thermally very stable ,because of its lattice energy . It is used as refractory materialin furnaces .A refractory MATERIAL is that which is not DEFORMED PHYSICALLY and chemically even upon strong HEATING .

Discussion

17.	"m" is the mass of a molecule, "k" is the Boltzmann constant, P is the pressure and T is the absolute temperature. The density of the gas is given by
Answer» <P>`(kT)/(p m)` `(PT)/(KM)` `(p m)/(kT)` `(pK)/(T m)` ANSWER :C

Discussion

18.	M+2H_2OtoM(OH)_2+H_2 which among the following metals does not undergo the above reaction at high temperature?
Answer» Be Ba Ca Sr Answer :A

Discussion

19.	Lysione is used as
Answer» DISINFECTANT germ treating eye diseases to RAISE VITALITY of HUMAN system Solution :Lysione is USED as a disinfectant.

Discussion

20.	Lyophillic collids are stable due to
Answer» CHARGE on the particles Large SIZE of the particle Small size of the particle layer of DISPERSION MEDIUM on their particles. Answer :D

Discussion

21.	lUPAC name of the compound is CH_(3)-CH = underset(CH_(2)-CH_(3))underset(\|)C-CH_(3)
Answer» 2-Ethyl-2-butene 3-Ethyl-2-butene 3-Methyl-3-pentene 3-Methyl-2-pentene SOLUTION :IUPAC NOMENCLATURE of RULES

Discussion

22.	Lung diseases are four times more in urban areas than in rural areas. This is due to the presence of
Answer» `SO_(2)` `CO_(2)` `N_(2)` Steam Answer :A

Discussion

23.	Luminosity observed as a result of scattering of light by particles is observed in
Answer» Suspensions Colloidal solution True solution None of these Answer :B

Discussion

24.	Lucas test is done for
Answer» ALKYL halides ALCOHOLS acids aldehydes Solution :Refer to DISTINCTION between `1^(@), 2^(@)` and `3^(@)` alcohols in Comprehensive Review.

Discussion

25.	Lucas test can be used to distinguished between
Answer» PHENOL and p-cresol Propan-1-ol and ethanol Butan-1-ol and 2-methylpropan-2-ol Ethanol and glycol Solution :`underset((1^(@) "Alcohol"))underset("Butan-1-ol")(H_(3)C-CH_(2)-CH_(2)-CH_(2)-OH) " " underset((3^(@) " Alcohol"))underset("2-Methylpropan-2-ol")(H_(3)C-underset(OH)underset(\|)overset(CH_(3))overset(\|)(C)-CH_(3))`

Discussion

26.	Lucas reagent is equimolar solution of
Answer» Conc. `H_(2)SO_(4)` and conc. `HNO_(3)` Conc. `HNO_(3)` and ANHY. `ZnCl_(2)` Conc. `HCL` and anhy. `ZnCl_(2)` Conc. `H_(2)SO_(4)` and anhy. `ZnCl_(2)` ANSWER :C

Discussion

27.	lsostructural species are those which have the same shape and hybridization. Among the given species identify the isostructural pairs.
Answer» `[NF_(3) and BF_(3) ]` `[BF_(4)^(-) and NH_(4)^(+)]` `[BCl_(3) and BrCl_(3)]` `[NH_(3) and NO_(3)^(-)]` Solution :`[BF_(4)^(-) and NH_(4)^(+)]` (A) `NF_(3)` is PYRAMIDAL while ` BF_(3)` is planar triangular. (B) `BF_(4)^(-) and NH_(4)^(+)` ION both are tetrahedral so `SP^(3)` hybridization. (C) `BCl_(3)` istriangular planar while `BrCl_(3)` is T shaped. (D) `NH_(3)` is pyramidal and `NO_(3)^(-)` is triangular planar.

Discussion

28.	lsoelectronic molecules and ions have identical bond orders. Explain by examples.
Answer» Solution :Bond ORDER in Isoelectronic molecules/ions : If two or more diatomic MOLECULE or ION are isoelectronic so its bond order is same. Example-1 : `F_(2) and O_(2)^(-2) ` both have same 18 electrons and bond order is ALSO same 1. `F_(2) : F - F and O_(2)^(-2) (O - O)^(2-)` Example-2 : `N_(2),` CO and `NO^(+)` are isoelectronic and containing 14 ELECTRON and triple bond in it.

Discussion

29.	Lower the critical temperature of a gas …………. is its rate of liquefation.
Answer» There is no relation between critical temperature and rate of liquefaction. Faster MODERATE Slower Solution :When cooled mixture of TWO gases having DIFFERENT critical temperature then gas which have more critical temperature will liquified first and earlier because, when cooled mixture, gas liquified first whose value of critical temperature is more in opposite way, ..Gas liquify slow whose value of critical temperature is low... e.g., Critical temperature of `H_(2)` and He gas is 33.2K and 5.3 K RESPECTIVELY. so when cooled mixture of Hc, `H_(2)` then Hc gas liquified first.

Discussion

30.	Lower carboxylic acids are soluble in water due to
Answer» Low MOLECULAR weight Hydrogen bonding Dissociation into ions Easy hydrolysis Solution :Lower CARBOXYLIC ACIDS are soluble in WATER due to hydrogen bonding

Discussion

31.	Low pressure favours those gaseous reactions which are accompained by ……… in the total number of moles.
Answer» ANSWER :INCREASE

Discussion

32.	Low concentration of oxygen in the blood and tissue of people living at high altitude is due to …………………..
Answer» SOLUTION :LOW ATMOSPHERIC PRESSURE

Discussion

33.	lonic nature of hydrides is
Answer» `BeH_(2) gt MgH_(2) gt CaH_(2) gt SrH_(2) gt BaH_(2)` `BeH_(2) lt MgH_(2) lt CaH_(2) lt SrH_(2) lt BaH_(2)` `BeH_(2) lt MgH_(2) lt CaH_(2) gt SrH_(2) lt BaH_(2)` `BeH_(2) lt MgH_(2) lt CaH_(2) lt SrH_(2) lt BaH_(2)` Solution :The ionic nature of hydrides of IIA group elements increases down the group as ELECTRO POSITIVE nature increases down the group.

Discussion

34.	Londonm force is ………
Answer» DIRECTLY proportional to `(1)/(r^(6))`. directly proportional to `r^(6)`. Inversely proportional to pressure of barometer. All of these ANSWER :A

Discussion

35.	London smog is __________ in nature whereas photochemical smog is ______in nature.
Answer» ANSWER :REDUCING , OXIDIZING

Discussion

36.	London smog is found in
Answer» SUMMER during DAY time Summer during MORNING time Winter during morning time Summer during day time Answer :C

Discussion

37.	London forces are stronger, except in
Answer» bigger atoms or molecules than in smaller atoms or molecules more SPREAD SHAPED molecules than less spread molecules 2,2-dimethyl propane than in pentane `I_2` is more polarisable than `F_2` ANSWER :C

Discussion

38.	London Force is which type of force ?
Answer» IONIC COVALENT VAN der Waal Hydrogen Bond ANSWER :C

Discussion

39.	"log"(k_P)/(k_C)1-log RT=0 is true relationship for the following reaction
Answer» `PCl_5 harr PCl_3+Cl_2` `SO_2+O_2 harr 2SO_3` `N_2+3H_2 harr 2NH_3` both B & c Solution :`log(K_(P))/(K_(C))+log RT =0 IMPLIES ((K_(P))/(K_(C)))=(RT)^(-1)` `implies Delta NG = -1`

Discussion

40.	lodoform can be usetd as ………………… .
Answer» SOLUTION :ANTISEPTIC

Discussion

41.	lodine molecule dissociates into atoms after absorbing light of 4500Å. If one quantum of radiation is absorbed by each molecule, calculate the kinetic energy of iodine atoms. Bond energy of I_(2) is 240kJmol^(-1)
Answer» ANSWER :`2.16xx10^(-20) J`

Discussion

42.	ln which one of the following species the central atom has the type of hybridization which is not the same as that present in the other three ?
Answer» `SF_(4)` `I_(3)^(-)` `SbCl_(5)^(2-) ` `PCl_(5)` Solution :`SbCl_(5)^(2-) ` `SbCl_(5)^(2-): (5 + 5 + 2)/(2)= 6 " means " sp^(3) d^(2)` `I_(3)^(-), SF_(4) and PCl_(5)` : all have `sp^(3)` d HYBRIDIZATION .

Discussion

43.	ln which of the following sets all the species are paramagnetic in nature ?
Answer» `O_(2),O_(2)^(2+) , N_(2)^(2-)` `B_(2) ,C_(2),H_(2)` `O_(2)^(-), O_(2)^(+) ,O_(2)` `N_(2)^(+) , O_(2)^(+),F_(2)^(+)` ANSWER :C::D

Discussion

44.	ln vulcanization, the formation of sulphur bridge between different chains make rubber harder ai stronger
Answer» `H_(2)C-CH-overset(CL)overset(\|)(C)=CH_(2) and H_(2)C=CH-CH=CH_(2)` `H_(2)C=CH-CH=CH_(2) and H_(5)C_(6)-CH=CH_(2)` `H_(2)C=CH-CN and H_(2)C-CH-CH=CH_(2)` `H_(2)C=CH-CN and H_(2)C=CH-overset(Cl)(C)=CH_(2)` Answer :C

Discussion

45.	Living in the atmosphere of CO is dangerous because it..........
Answer» Combines with `O_(2)` PRESENT INSIDE to form `CO_(2)` Reduces organic MATTER of tissues Combines with HAEMOGLOBIN and makes it incapable to absorb oxygen Combines with haemoglobin and makes it incapable to absorb oxygen Solution :Combines with haemoglobin and makes it incapable to absorb oxyge

Discussion

46.	Lithopone is ……….
Answer» `BaO+ZnSO_(4)` `ZnO+BaSO_(4)` `BaS+ZnSO_(4)` `ZnS+BaSO_(4)` Solution :`ZnS +BaSO_(4)` is lithopone USED as white PIGMENT.

Discussion

47.	Lithium exhibits diagonal relationship with
Answer» SOLUTION :MAGNESIUM

Discussion

48.	Lithium shows diagonal relationship with ……….. .
Answer» sodium magnesium calcium aluminium Answer :B

Discussion

49.	Lithium shows diagonal relationship with
Answer» sodium MAGNESIUM calcium aluminium Solution :magnesium(DIAGRAM PENDING)

Discussion

50.	Lithium salts are mostly hydrated like LiCl*2H_(2)O due to
Answer» MAXIMUM IONISATION enthalpy maximum degree of hydration of `Li^(+)` maximum hygroscopic nature maximum chemical reactivity. Solution :`Li^(+)` has maximum degree of hydration due to smallest SIZE in the grou phence its salts are MOSTLY HYDRATED.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Magnesium burns with a _____ flame.

Magnesium on heating separately with aqueousferric chloride and ammonium chloride gives the same gas, X,X is inflammable and reacts with metal to form electrovalent soild ,which on hydrolysis gives the same gas .Predict the gas X.

Magnesium metals burns in air to give a white ash . When this ash is treated with water , the odour of ammonia can be detected . Explain .

Magnesium loses electrons successively to form Mg^(+),Mg^(2+)andMg^(3+) ions . Which step will have the highest ionisation energy and why ?

Magnesium may be called a refactory because it

Soaps do not work in hard water containing calcium and magnesium ions because

Magnesium content present in aqueous solution can be precipitated using either aqueous sodium carbonate or aqueous barium hydroxide .Write equation and discuss.

Magnesium chloride is an ionic substance. It is also volatile. It does not impart flame colour. Why?

Magnesium burns in the atmosphere of the following gases ?

Magnesium burns in air forming …….and ……. .

Write the equations for the following and balance them Magnesium reacts with nitrogen to give magnesium nitride.

Magnesite is a mineral of

Magnesia is a refractory material.Explain.

"m" is the mass of a molecule, "k" is the Boltzmann constant, P is the pressure and T is the absolute temperature. The density of the gas is given by

M+2H_2OtoM(OH)_2+H_2 which among the following metals does not undergo the above reaction at high temperature?

Lysione is used as

Lyophillic collids are stable due to

lUPAC name of the compound is CH_(3)-CH = underset(CH_(2)-CH_(3))underset(|)C-CH_(3)

Lung diseases are four times more in urban areas than in rural areas. This is due to the presence of

Luminosity observed as a result of scattering of light by particles is observed in

Lucas test is done for

Lucas test can be used to distinguished between

Lucas reagent is equimolar solution of

lsostructural species are those which have the same shape and hybridization. Among the given species identify the isostructural pairs.

lsoelectronic molecules and ions have identical bond orders. Explain by examples.

Lower the critical temperature of a gas …………. is its rate of liquefation.

Lower carboxylic acids are soluble in water due to

Low pressure favours those gaseous reactions which are accompained by ……… in the total number of moles.

Low concentration of oxygen in the blood and tissue of people living at high altitude is due to …………………..

lonic nature of hydrides is

Londonm force is ………

London smog is __________ in nature whereas photochemical smog is ______in nature.

London smog is found in

London forces are stronger, except in

London Force is which type of force ?

"log"(k_P)/(k_C)1-log RT=0 is true relationship for the following reaction

lodoform can be usetd as ………………… .

lodine molecule dissociates into atoms after absorbing light of 4500Å. If one quantum of radiation is absorbed by each molecule, calculate the kinetic energy of iodine atoms. Bond energy of I_(2) is 240kJmol^(-1)

ln which one of the following species the central atom has the type of hybridization which is not the same as that present in the other three ?

ln which of the following sets all the species are paramagnetic in nature ?

ln vulcanization, the formation of sulphur bridge between different chains make rubber harder ai stronger

Living in the atmosphere of CO is dangerous because it..........

Lithopone is ……….

Lithium exhibits diagonal relationship with

Lithium shows diagonal relationship with ……….. .

Lithium shows diagonal relationship with

Lithium salts are mostly hydrated like LiCl*2H_(2)O due to

London smog is ____ in nature whereas photochemical smog is in nature.