94420 + Interview Questions in Chemistry in Class 12 Page 1774 InterviewSolution

88651.	A mineral(X) concentratedby froth floatation process was roasted in a reverberatory furance go give two compojnd (A) and (B) whichwere later partially oxidizes, B was more easily oxidised than A) to give compounds (C ) and (D) respectively. The roasted ore was mixed with silica and some powdered coke and later smalted when two layers of moltenmass was obtained-the upper layer was that of salg (E) while the lower layer is called matte (F). The molten mattel was then transferred to a bessemer converter and a blastof hot air and sand waspassed through it when the metal (Y) was obtained.Identify the mineral (X), the meta (Y) and the compounds (A-F)
Answer» Solution :(i) Sincemineral (X) is concentratedby frothfloatationprocess, it mustbeasulphidemineral (ii) Sinceduringroasting, the mineral(X) formedtwo compounds(A) and(B),therefore, the mineral consistsoftwo METALS, maybe , Cu andFe. If thisobservationiscorrect,thenthemineralconsists fo twometals, may be , Cu andFe.Ifthis observationis correct, thenthemineral(X) iscopperpyrites. `underset ("Copper pyriter (X)")( 2CU Fe S_2)+O_ 2overset (Delta ) tounderset("(A)") (Cu_2S )+underset("(B)") (2FeS) +SO_ 2` Since Fe ismorereactivethen Cu,therefore , FeS(B) ispreferentiallyoxidisedto FEO then`Cu_ 2S`isoxidisedto` Cu _ 2O`. Ifat allany` Cu_ 2O` isformed, itcombineswithFeS to form` Cu_ 2 S`. Duringsmelting, FeOcombineswith ` SiO_ 2`to formferroussilicateslage (E). `FeO +SiO_ 2tounderset ("FERROUS silicate (E)") ( FeSiO_3) ` The matte (F) mainlyconsistsofamixtureof`Cu_ 2 S `withsomeunchangesFeS. Duringbessemerization,FeS isoxidised to FeOwhichcombineswith `SiO_2`toform` FeSiO_ 3`slag ` Fe O+SiO_ 2toFe SiO_ 3(slag )` Some of` Cu_ 2 S`isfirstoxidized to`Cu_ 2 O`which thenreactswithremaining` Cu_ 2 S`to formcoppermetal(Y). `2Cu_ 2S+3 O_ 2to2 Cu_ 2O+2SO_ 2,2Cu_ 2O+Cu_ 2Stounderset("Copper metal (E)") ( 6 Cu) +SO _ 2` Thus,`X = Cu FeS_ 2`(copperpyrites ),Y = Cu, A =` Cu_ 2S`,B =FeS,C =` Cu_2 O`,D = FeO ,E =` FeSi O _ 3`.

Discussion

88652.	A mineral usually has large amount of undesirable impurities. These imputitiesare called
Answer» MATRIX of gangue Slag Flux Ore Answer :A

Discussion

88653.	A mineral is usually accompanied by large amount of undesirable impurities called:
Answer» MATRIS or gangue Slag Flux Ore Answer :A

Discussion

88654.	The removal of impurities from a crude metal is called :
Answer» MATRIS or gangue Slag Flux Ore Answer :A

Discussion

88655.	A mineral having the formula AB_2 crystallizes in the cubic close-packed lattice, with the A atoms occupying the lattice points. What are the coordination numbers of the A and B atoms?
Answer» ANSWER :8,4

Discussion

88656.	A mineral is known as ore if metal
Answer» The metal PRESENT in the MINERAL is costly A metal can be EXTRACTED from it A metal can be PROFITABLY extyracted from it A mineral cannot be extracted from it Answer :C

Discussion

88657.	A mineral having the formula AB_(2) crystallizes in the ccp lattice, with A atoms occupying the lattice points. The coordination number of A and B atoms in its structure are
Answer» 4,8 4,4 8,8 8,4 Solution :Since A atoms OCCUPY the lattice POINTS , B atoms will be in all TETRAHEDRAL SITES. `:.` Coordination NUMBER of B = 4 Coordination number of A = 8

Discussion

88658.	A mineral having the formula AB_2 crystallizes in the c.c.p. lattice, with A atoms occupying the lattice points. The CN of A is 8 and that of B is 4. What percentage of the tetrahedral sites is occupied by B atoms? (CsCl = 168.40
Answer» `7.014 xx 10^(-23) CC` `2.81 xx 10^(-32) C` `6.022 xx 10^(23) cc` `3.004 xx 10^(-23)` cc Answer :D

Discussion

88659.	In a compound XY_(2) O_(4) , oxide ions are arranged in CCP and cations X are present in octahedral voids. Cations Y are equally distributed between octahedral and tetrahedral voids. The fraction of the octahedral voids occupied is :-
Answer» `(1)/(6)` `(1)/(8)` `(1)/(4)` `(1)/(2)` ANSWER :D

Discussion

88660.	A mineral contained MgO= 31.88%, SiO_(2)=63.37% and H_(2)O=4.75%. Show that the simplest formula for the mineral is H_(2)Mg_(3)Si_(4)O_(12). (H=1, Mg=24, Si=28, O=16)
Answer» Solution :Suppose the weight of the mineral is 100g. Then weight of MGO= 31.88g weight of `SO_(4)=` 63.37g, weight of `H_(2)O`=4.75g. Moles of Mg in MgO= `1 XX` moles of MgO `=(31.88)/(40)=0.797` Moles of Si in `SiO_(2)=1 xx` moles of `SiO_(2)` `=(63.37)/(60)=1.0561` Moles of H in `H_(2)O=2 xx` moles of `H_(2)O` `=(2xx4.75)/(18)= 0.5278` moles of O = moles of O in MgO+ moles of O in `SiO_(2)` + moles of O in `H_(2)O` `=1 xx` moles of MgO +2 `xx` moles of `SiO_(2)+1 xx` moles of `H_(2)O` `=(31.88)/(40) + (2 xx 63.37)/(60)+ (4.75)/(18)=3.172` Moles of O= 3.172 Now, by inspection, we have moles of H= 0.5278 `=0.2639 xx 2` moles of Mg= 0.797 `~~0.2639 xx 3` moles of Si=1.0561 `~~0.2639 xx 4` moles of O=3.172 `~~0.2639 xx 12` `therefore H: Mg: Si: O= 2: 3: 4: 12` The FORMULA is `H_(2)Mg_(3)Si_(4)O_(12)`

Discussion

88661.	A mineral contain following tetrameric anion in which ●=Si ○=oxygen Select correct option (s) about anion in mineral-
Answer» Formula of ANION is `(SiO_(3))_(n)^(2n)` (where n=4) The total 10 negativecharges are present in this anion It has three SHARED oxygen/corners and ten unshared oxygen/corners. it is non polar Answer :A

Discussion

88662.	(A) Milk is an example of water in oil emulsions (R ) Emulsions contains liquid dipersed in solid
Answer» Both (A) and (R ) are true and (R ) is the CORRECT EXPLANATION of (A) Both (A)and (R ) are true and (R ) is not the correct explanation of (A) (A) is true but (R ) is false Both (A) and (R ) are false Answer :D

Discussion

88663.	(A)Milk is a naturally occuring stable emulsion . (R ) Milk is an example of oil in water type emulsion
Answer» Both (A) and (R) are true and (R) is the CORRECT EXPLANATION of (A) Both (A) and (R) are true and (R) is not the correct explanation of (A) (A) is true but (R) is false (A) is false but (R) is true Answer :B

Discussion

88664.	A microscope using suitable photons is employed to locate an electron within a distance of 0.1Å. What is the uncertainty involved in measurement of its velocity?
Answer» ANSWER :`5.76xx10^(6)MS^(-1)`

Discussion

88665.	A micelle formed during the cleansing action by soap is
Answer» A DISCRETE particle of SOAP Aggeregated particles of soap and DIRT A discrete particle of dust An aggregated particle of dust and WATER Answer :B

Discussion

88666.	A [M(H_(2)O)_(6)]^(2+) complex typically absorbs at around 600 nm. It is allowed to react with ammonia to form a new complex [M(NH_(3))_(6)]^(2+) that should have absorption at
Answer» 800 nm 580 nm 620 nm 320 nm Answer :D

Discussion

88667.	A [M(H_(2)O)_(6)]^(2+) complex typically absorbs at around 600 n. it is allowed to react with ammonia to form a new compelx [M(NH_(3))_(6)]^(2+) that should have absorption at:
Answer» 800 nm 580 nm 620 nm 320 nm Solution :As `NH_(3)` is sronger ligand than `H_(2)O`, hence CFSE VALUE for `[M(NH_(3))_(6)]^(3+) gt CFSE` of `[M(H_(2)O)_(6)]^(2+)` THEREFORE, absorption SHIFTS to smaller wavelength. Also DIFFERENCE between splitting POWER of `NH_(3)` and `H_(2)O` is not very high.

Discussion

88668.	(A) Mg metal is not used for reduction of Al_(2) O_(3) thermodynamically (R)The process will be uneconomical
Answer» Both (A) and (R) are TRUE and (R) is the CORRECT EXPLANATION of (A) Both (A) and (R) are true and (R) is not the correct explanationof (A) (A) is true but (R) is false Both (A) and (R) are false Answer :A

Discussion

88669.	(A): Methylisocyanide can be easily hydrolysed by acids but not by alkalies. (R): The carbon atom of isocyanide group in methyl isocyanide carries a negative charge which readily accepts the proton and repels the OH^(-) ion.
Answer» Both A & R are TRUE, R is the correct EXPLANATION of A Both A & R are true, R is not correct explanation of A A is true, R is false A is false, R is true Answer :A

Discussion

88670.	(A) M_((g))^(-)toM_((g)) (B) M_((g))toM_((g))^(+) (C) M_((g))^(+)toM_((g))^(2+) (D) M_((g))^(2+) to M_((g))^(3+) minimum and maximum I.P. would be:
Answer» A,B B,C C,D A,D Solution :`I.P. prop (+" ve CHARGE")/("-ve charge")`.

Discussion

88671.	(A) Methoxy benzene can be prepared by the reaction of C_6H_5 ONa and CH_3 Br but not by the reaction of C_6H_5Brwith CH_3 ONa(R) C_6H_5-Bris not a good substrate for SN? reaction because attack of nucleophile from back side of leaving group is hindered by the ring and also double bond character will be developed between carbon and bromine
Answer» Both (A) and (R) are TRUE and (R) is the CORRECT EXPLANATION of (A) Both (A) and (R) are true and (R) is not the correct explanation of (A) (A) is true but (R) is false Both (A) and (R) are false Answer :A

Discussion

88672.	A methyl glucoside can be converted to the _______ anhydride in the presence of pyridine. Identify the produce formed.
Answer» tetramethyl pentamethyl trimethyl hexamethyl Solution : This reaction is just a multiple williamson synthesis. The hydroxyl groups of monosaccharides are more acidic than those of ordinary alcohols because the monosaccharides contains so many electronegative oxygen atoms, all of which exert electron-withdrawing inductive effects no nearby hydroxyl groups. In aqueous `NaOH`, the hydroxyl groups are CONVERTED to alkoxide ions, and each of these, in TURN reacts with dimethyl sulphate in an `S_(N)^(2)` reaction to yield a methyl ether. The process called exhaustive methylation. The methoxy groups at `C_(2), C_(3), C_(4)` and `C_(6)` of the pentmethyl derivative are ordinary ether groups. Consequently, these groups are stable in dilute aqueous acid (remember, to cleave ethers requires HEATING with come. `HBr` or `HI`). However, the methoxy group at `C1` is different from others because it is a part of an acetal linkage (it is GLYCOSIDIC). Therefore, treating the pentamethyl derivative with dilute aqueous acid causes hydrolysis of this glycosidic methoxy group and produces 2,3,4,6- teta `O`-methyl - `D-` glucose (The `O` in this name means that methyl groups are bonded to oxygen atoms).

Discussion

88673.	A : Methane cannot be prepared by kolbe electrolytic reaction. R : In this reaction alkane is liberated at anode.
Answer» If both ASSERTION & Reason are true and the reason is the correct explanation of the assertion, then MARK (1). If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2) if Assertion is true statement but Reason is FALSE, then mark (3) If both Assertion and Reason are false statements, then mark (4) Answer :2

Discussion

88674.	(A) Metals of 4d and 5d series have greater enthalpies of atomization than the corres- ponding 3d series. (R) 4d and 5d series elements are smaller than 3d series
Answer» Both (A) and (R) are TRUE and (R) is the CORRECT EXPLANATION of (A) Both (A) and (R) are true and (R) is not the correct explanation of (A) (A) is true but (R) is FALSE Both (A) and (R) are false Solution : (A) is true but (R) is false

Discussion

88675.	(A): Metals like Sn and Pb can be refined by liquation (R) : Sn and Pb are readily fusible and can be separated from less fusible impurities on heating
Answer» Both A & R are true, R is the correct EXPLANATION of A Both A & R are true, R is not correct explanation of A A is true, R is FALSE A is false, R is true Answer :A

Discussion

88676.	(A) Metallic solids are electrical and thermal conductors (R) Metallic solids have mobile electrons
Answer» Both (A) and (R) are true and (R) is the CORRECT explanation of (A) Both (A) and (R) are true and (R) is not the correct explanation of (A) (A) is true but (R) is false Both (A) and (R) are false Answer :A

Discussion

88677.	A: Metallurgy of Ag from Argentite is known as hydro-metallurgy R: Argentile is Ag_2S.
Answer» If both Assertion & Reason are TRUE and the reason is the CORRECT EXPLANATION of the assertion, then mark (1). If both Assertion & Reason are true but the reason is not the correct explanation of the assertion, then mark (2) If Assertion is true statement but Reason is false, then mark If both Assertion and Reason are false statements, then mark (4) Answer :B

Discussion

88678.	A metallic oxide which imparts purple colour to pottery is :
Answer» LEAD oxide Copper oxide Sodium oxide Manganese dioxide Answer :D

Discussion

88679.	A metallic oxide reacts with water to from its hydroxide, hydrogen peroxide and also liberatesoxygen. The metallic oxide could be
Answer» CAO `KO_(2)` `Li_(2)O` `Na_(2)O_(2)` SOLUTION :`UNDERSET("superoxide")underset("Potassium")(2KO_(2)+2H_(2)O rarr 2KOH + H_(2)O_(2)+O_(2) uarr)`

Discussion

88680.	A metallic nitrate (A) on strong heating leaves behind a residue along with liberation of gases. The metallic nitrate on treatment with H_(2)S//H^(+) gives a black precipitate (B)^(-) insoluble in hot dilute nitric acid, but the precipitate dissolves in aquaregia. Compound B is
Answer» `Ag_(2)S` `CuS` `HgS` `PBS` SOLUTION :`underset((A))(HG(NO_(3))_(2))rarrHg+NO_(2)+O_(2)` `darrH_(2)S//H^(+)` `underset((B))(HgS)` `Hg(NO_(3))_(2)+NH_(3)+H_(2)OrarrHgO` `Hg(NH_(2))NO_(3)darr+NH_(4)^(+)`( White ppt of mixed composition)

Discussion

88681.	A metallic nitrate (A) on strong heating leaves behind a residue along with liberation of gases. The metallic nitrate on treatment with H_(2)S//H^(+) gives a black precipitate (B)^(-) insoluble in hot dilute nitric acid, but the precipitate dissolves in aquaregia. Compound A is
Answer» `AgNO_(3)` `CU(NO_(3))_(2)` `Pb(NO_(3))_(2)` `Hg(NO_(3))_(2)` SOLUTION :`underset((A))(Hg(NO_(3))_(2))rarrHg+NO_(2)+O_(2)` `darrH_(2)S//H^(+)` `underset((B))(HgS)` `Hg(NO_(3))_(2)+NH_(3)+H_(2)OrarrHgO` `Hg(NH_(2))NO_(3)darr+NH_(4)^(+)`( White PPT of MIXED composition)

Discussion

88682.	A metallic element 'X' has cubic lattic. Each edge of the unit cell is 2.0Å and its density is 2.5 g cm^(-3). Number of atoms in 200g of the metal are :
Answer» `1 xx 10^(20)` `1 xx 10^(22)` `1 xx 10^(24)` `1 xx 10^(25)` Solution :Volume of unit CELL `= ( 2.0 xx 10^(-8) cm )^(3)` `= 8 xx 10^(-24) cm^(3)` Density `= 2.5 g cm^(-3)` Mass of unit cell `= 8 xx 10^(-24) xx 2.5 ` `= 20 xx 10^(-24) g ` No. of unit cells in 200G`= ( 200)/( 20 xx 10^(-24))` `= 1 xx 10^( 25)` Since metallic element has simple cubic lattice, number of atoms in a unit cell =1 No. of atoms in 200g of metal `=1 xx 10^(25) xx 1 ` `= 1 xx 10^(25) ` atoms

Discussion

88683.	A metallic element has cubic lattice. Each edge of the unit cell is 3.0 A. The density of the metal is 8.5 g/cc. How many unit cells will be present in 50 g of the metal?
Answer» ANSWER :`2.178 XX 10^(23)`

Discussion

88684.	A metallic element exists as a cubic lattice. Each edge of the unit cell is 2.88 Å and the density of the metal is 7.2gcm^(-3). The number of unit cells in 100 g of the metal is
Answer» `5.82xx10^(23)` `6.023xx10^(23)` `8.52xx10^(23)` NONE of these Answer :A

Discussion

88685.	A metallic element crystallizes into a lattice containing a sequence of layers of ABABAB "…............". Any packing of spheres leaves out voids in the lattice. What percentage by volume of this lattice is empty space ?
Answer» 0.74 0.26 0.5 0.2 Answer :B

Discussion

88686.	A metallic element crystallizes into a lattice contained sequence of layers ABABAB…. Any packing of sphere leaves out voilds in the lattice.The percentage by volume of this lattice as empty space is
Answer» `26%` `74%` `50%` `85%` ANSWER :A

Discussion

88687.	A metallic crystal cystallizes into a lattice containing a sequence of layers ABABAB…. Any packing of spheres leaves out voids in the lattice. What percentage by volume of thislattice is empty spece?
Answer» ANSWER :26

Discussion

88688.	A metallic element crystallises into a lattice containing a sequence of layers of ABABAB.. Percentage of empty space (by volume) is:
Answer» 0.52 0.26 0.5 0.74 Answer :B

Discussion

88689.	A metallic element crystallises into a lattice containing a sequence of layers ABABAB... . Any packing of spheres leaves out voids in the lattice. What percentage by volume of this lattice is empty space?
Answer» SOLUTION :The EMPTY SPACE in h.c.p. or c.c.p. ARRANGEMENT is same as for f.c.c. 25.94%

Discussion

88690.	A metallic crystal crystallizes into lattice containing a sequence of layers AB,AB,AB. . .. . . . .. ...The percentage of free space in this lattice is
Answer» 0.74 0.26 0.32 0.48 Solution :It is FCC PACKING Volume occupied`=(4(4)/(3)m^(3))/(a^(3)) [4r=sqrt(2)arArra=2sqrt(2)r]` `=(4xx(4)/(3)m^(3))/((2sqrt(2)r)^(3))=(16)/(3)xx(1)/(16sqrt(2))pi=(pi)/(3sqrt(2))=(3.142)/(3xx1.414)=0.74` Volume occupied is 74%, FREE space =26%

Discussion

88691.	A metallic chloride A when treated with sodium hydroxide and H_(2)O_(2) gives a yellow solution due to the formafion of compound B. The colour of this solution changes to orange yellow when dilute H_(2)SO_(4) is added to it due to formation of (C). Compound, (D) when heated with (C) in presence of conc. H_(2)SO_(4) a red volatile liquid E is formed. E dissolves in NaOH giving yellow solution B, which changes to yellow ppt. Fon treatment with lead acetate. (C) on reaction with NH_(4)Cl gives G which on heating gives colourless gas (H and a green residue (1). Identify (A) to (I).
Answer» SOLUTION :`UNDERSET((A))(2CrCI_(2))+10NaOH+3H_(2)O_(2)tounderset((B))(2Na_(2)CrO_(4))+6NaCl+8H_(2)O` `underset((B))(2Na_(2)CrO_(4))+H_(2)SO_(4)tounderset((C))(Na_(2)Cr_(2)+O_(7))+Na_(2)SO_(4)+H_(2)O` `underset((D))(4NaCI)+Na_(2)Cr_(2)O_(7)+6H_(2)SO_(4)tounderset((E))(2CrO_(2)Cl_(2))+6NaHSO_(4)+3H_(2)O`

Discussion

88692.	A metalliccarbideon treatmentwith water givesa colourless gas whichburnsreadilyin airandgivesa redprecipitate with Cu_(2) CI_(2) and NH_(4) OH. Themetalcarbideis :
Answer» `CaC_(2)` `Ai_(4) C_(3)` `SiC` all ANSWER :A

Discussion

88693.	(A): Metalcarbonyls can be called organometallics. (R): Metal carbonyls do contain metal-carbon bond.
Answer» Both A & R are true, R is the correct EXPLANATION of A Both A & R are true, R is not correct explanation of A A is true, R is FALSE A is false, R is true Answer :A

Discussion

88694.	A metal X ( at. Mass = 60) has a bodycentred cubic crystal structure. The density of the metal is 4.2 g cm^(-3) . The volume of unit cell is
Answer» `8.2 xx 10^(-23) cm^(3)` `4.75 xx 10^(-23) cm^(3)` `3.86 xx 10^(23) cm^(3)` `3.86 xx 10^(-23) cm^(3)` SOLUTION :MASS of unit cell `= ( 2 xx 60)/( 6.02 xx 10^(23))` DENSITY `= ( " Mass")/( "VOLUME")` `4.2 = ( 2XX 60)/( 6.02 xx 10^(23) xx v )` or `V = ( 2 xx 60)/( 6.02 xx 10^(23) xx 4.2 )` `= 4.75 xx 10^(-23) cm^(3)`

Discussion

88695.	A metal wire carries of current of 1 ampere. How many electrons pass a paint in the wire in 1 second. ?
Answer» Solution :Charge in coulomb = current in ampere `xx` time (s) Since 1 F (96,500 coulombs) of electricity is carried out by 1 mole of electrons, i.e., `6.022 xx 10^(23)` electrons, therefore, 1 coulomb shall INVOLVE `6.022 xx 10^(23)//96500`, i.e, `6.24 xx 10^(18)` electrons. Thus, `6.24 xx 10^(18)` electrons pass a POINT in the WIRE in 1 SECOND.

Discussion

88696.	A matel wire carries a current of one amp. How many electrons pass a point in the wire in one sec.
Answer» ANSWER :`6.24xx10^(18)`

Discussion

88697.	A metal wire carries a current of 4 ampere. How many electrons pass through a point in the wire in one second?
Answer» SOLUTION :Total charge passed in `1` sec. `= 4 xx 1` `= 4` coulomb `(because Q = i xx t)` `:. 1` FARADAY or `96500 C` current CARRIED by `= 6.023 xx 10^(23)` electrons `:. 4` coulomb current carried by `= (6.023 xx 10^(23) xx 14)/(96500)` `= 2.5 xx 10^(9)` electrons

Discussion

88698.	A metal which is refined by polling is _________.
Answer» sodium blister copper zinc silver Answer :B

Discussion

88699.	A metal which is refined by poling is
Answer» Sodium Blister copper Zinc Silver Solution :Poling is useed for PURIFICATION of METAL contian own axide as IMPURITY ` e.g. Cu_(2)O` in CU, `SnO_(2)` in Sn.

Discussion

88700.	A metal which has no effect on a solution of mercury chloride is
Answer» Ag Al Fe Zn Answer :A

Discussion

Explore topic-wise InterviewSolutions in .

A mineral usually has large amount of undesirable impurities. These imputitiesare called

A mineral is usually accompanied by large amount of undesirable impurities called:

The removal of impurities from a crude metal is called :

A mineral having the formula AB_2 crystallizes in the cubic close-packed lattice, with the A atoms occupying the lattice points. What are the coordination numbers of the A and B atoms?

A mineral is known as ore if metal

A mineral having the formula AB_(2) crystallizes in the ccp lattice, with A atoms occupying the lattice points. The coordination number of A and B atoms in its structure are

A mineral having the formula AB_2 crystallizes in the c.c.p. lattice, with A atoms occupying the lattice points. The CN of A is 8 and that of B is 4. What percentage of the tetrahedral sites is occupied by B atoms? (CsCl = 168.40

In a compound XY_(2) O_(4) , oxide ions are arranged in CCP and cations X are present in octahedral voids. Cations Y are equally distributed between octahedral and tetrahedral voids. The fraction of the octahedral voids occupied is :-

A mineral contained MgO= 31.88%, SiO_(2)=63.37% and H_(2)O=4.75%. Show that the simplest formula for the mineral is H_(2)Mg_(3)Si_(4)O_(12). (H=1, Mg=24, Si=28, O=16)

A mineral contain following tetrameric anion in which ●=Si ○=oxygen Select correct option (s) about anion in mineral-

(A) Milk is an example of water in oil emulsions (R ) Emulsions contains liquid dipersed in solid

(A)Milk is a naturally occuring stable emulsion . (R ) Milk is an example of oil in water type emulsion

A microscope using suitable photons is employed to locate an electron within a distance of 0.1Å. What is the uncertainty involved in measurement of its velocity?

A micelle formed during the cleansing action by soap is

A [M(H_(2)O)_(6)]^(2+) complex typically absorbs at around 600 nm. It is allowed to react with ammonia to form a new complex [M(NH_(3))_(6)]^(2+) that should have absorption at

A [M(H_(2)O)_(6)]^(2+) complex typically absorbs at around 600 n. it is allowed to react with ammonia to form a new compelx [M(NH_(3))_(6)]^(2+) that should have absorption at:

(A) Mg metal is not used for reduction of Al_(2) O_(3) thermodynamically (R)The process will be uneconomical

(A): Methylisocyanide can be easily hydrolysed by acids but not by alkalies. (R): The carbon atom of isocyanide group in methyl isocyanide carries a negative charge which readily accepts the proton and repels the OH^(-) ion.

(A) M_((g))^(-)toM_((g)) (B) M_((g))toM_((g))^(+) (C) M_((g))^(+)toM_((g))^(2+) (D) M_((g))^(2+) to M_((g))^(3+) minimum and maximum I.P. would be:

A methyl glucoside can be converted to the _______ anhydride in the presence of pyridine. Identify the produce formed.

A : Methane cannot be prepared by kolbe electrolytic reaction. R : In this reaction alkane is liberated at anode.

(A) Metals of 4d and 5d series have greater enthalpies of atomization than the corres- ponding 3d series. (R) 4d and 5d series elements are smaller than 3d series

(A): Metals like Sn and Pb can be refined by liquation (R) : Sn and Pb are readily fusible and can be separated from less fusible impurities on heating

(A) Metallic solids are electrical and thermal conductors (R) Metallic solids have mobile electrons

A: Metallurgy of Ag from Argentite is known as hydro-metallurgy R: Argentile is Ag_2S.

A metallic oxide which imparts purple colour to pottery is :

A metallic oxide reacts with water to from its hydroxide, hydrogen peroxide and also liberatesoxygen. The metallic oxide could be

A metallic nitrate (A) on strong heating leaves behind a residue along with liberation of gases. The metallic nitrate on treatment with H_(2)S//H^(+) gives a black precipitate (B)^(-) insoluble in hot dilute nitric acid, but the precipitate dissolves in aquaregia. Compound B is

A metallic nitrate (A) on strong heating leaves behind a residue along with liberation of gases. The metallic nitrate on treatment with H_(2)S//H^(+) gives a black precipitate (B)^(-) insoluble in hot dilute nitric acid, but the precipitate dissolves in aquaregia. Compound A is

A metallic element 'X' has cubic lattic. Each edge of the unit cell is 2.0Å and its density is 2.5 g cm^(-3). Number of atoms in 200g of the metal are :

A metallic element has cubic lattice. Each edge of the unit cell is 3.0 A. The density of the metal is 8.5 g/cc. How many unit cells will be present in 50 g of the metal?

A metallic element exists as a cubic lattice. Each edge of the unit cell is 2.88 Å and the density of the metal is 7.2gcm^(-3). The number of unit cells in 100 g of the metal is

A metallic element crystallizes into a lattice containing a sequence of layers of ABABAB "…............". Any packing of spheres leaves out voids in the lattice. What percentage by volume of this lattice is empty space ?

A metallic element crystallizes into a lattice contained sequence of layers ABABAB…. Any packing of sphere leaves out voilds in the lattice.The percentage by volume of this lattice as empty space is

A metallic crystal cystallizes into a lattice containing a sequence of layers ABABAB…. Any packing of spheres leaves out voids in the lattice. What percentage by volume of thislattice is empty spece?

A metallic element crystallises into a lattice containing a sequence of layers of ABABAB.. Percentage of empty space (by volume) is:

A metallic element crystallises into a lattice containing a sequence of layers ABABAB... . Any packing of spheres leaves out voids in the lattice. What percentage by volume of this lattice is empty space?

A metallic crystal crystallizes into lattice containing a sequence of layers AB,AB,AB. . .. . . . .. ...The percentage of free space in this lattice is

A metalliccarbideon treatmentwith water givesa colourless gas whichburnsreadilyin airandgivesa redprecipitate with Cu_(2) CI_(2) and NH_(4) OH. Themetalcarbideis :

(A): Metalcarbonyls can be called organometallics. (R): Metal carbonyls do contain metal-carbon bond.

A metal X ( at. Mass = 60) has a bodycentred cubic crystal structure. The density of the metal is 4.2 g cm^(-3) . The volume of unit cell is

A metal wire carries of current of 1 ampere. How many electrons pass a paint in the wire in 1 second. ?

A matel wire carries a current of one amp. How many electrons pass a point in the wire in one sec.

A metal wire carries a current of 4 ampere. How many electrons pass through a point in the wire in one second?

A metal which is refined by polling is _________.

A metal which is refined by poling is

A metal which has no effect on a solution of mercury chloride is