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.
| 4151. |
Using Gibb's free energy change Delta G^@=57.34kJ mol^-1 for the reaction X_2Y_(s)=2X^(+)+Y^(2-) (aq) Calculate the solubility product of X_2Y in water at 300 K |
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Answer» `10^-10` `logK_(sp)=(-57.37 times 10^3 J mol^-1)/(2.303 times 8.3 JK^-1 mol^-1 times 300K)` `log_10K_(sp)=-10` `THEREFORE K_(sp)=10^-10` `DeltaG^@=-2.303 RT LOG K_(eq)` `X_2Y(s) leftrightarrow 2X^(+) (aq)+Y^(2-) (aq)` `K_(eq)=([X^+]^2[Y^(2-)])/([X_2Y])` `K_(eq)=[X^+]^2[Y^(2-)]( thereforeX_2Y(s)=1)` `K_(eq)=K_(sp)` |
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| 4153. |
What are silicates and mention the types of silicates? |
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Answer» Solution :Silicates: The MINERAL which contains silicon and oxygen in tetrahedral `[SiO_(4)]^(4-)` UNITS linked together in different PATTERNS are called silicates. Types of silicates: (i) Ortho silicates (ii) PYRO silicates (iii) CYCLIC silicates (iv) Ino silicates (v) Phyllo silicates (vi) Tecto silicates |
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| 4154. |
When formic acid reacts with PCl_3is forms : |
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Answer» FORMYL CHLORIDE |
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| 4155. |
Which is the most stable carbocation |
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Answer» Iso-propyl Dispersal of positive charge increases with the INCREASE in the number of benzene ring. |
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| 4156. |
Whatweight of CO is required to form Re_(2) (CO)_(10) from 2 . 50 g of Re_(2) O_(7) accordingto theunbalanced reaction : Re_(2) O_(7) + CO to Re_(2) (CO)_(10) + (CO_(2)(Re = 186 . 2 , C = 1 and O = 16) |
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Answer» Solution :Suppose the RELATIVE moles of each reactantand product are as follows (just for convenience) `{:(Re_(2)O_(7)"" + CO "" to ""Re_(2) (CO)_(10)"+ "CO_(2)),(" a molesb molesc molesd moles "):}` Applying POAC for Re atoms, `{:(" moles of Re in " Re_(2) O_(7) =" moles of Re in " RE_(2) (CO)_(10)),(" "2 xx "moles of " Re_(2) O_(7) = 2 xx "moles of " Re_(2) (CO)_(10)),("Ra = 2c"),("ora = c" ):}`. . . (i) ApplyingPOAC for C atoms, moles of C atoms in CO = molesof C in `Re_(2) (CO)_(10) ` + moles of C in ` CO_(2)` `xx` molesof CO ` = 10 xx ` moles of `Re_(2) (CO)_(10) + 1 xx` moles of `CO_(2)` or b = 10 c + d. . . (II) moles of O in `Re_(2) O_(7) ` + molesof O in CO = molesof O in `Re_(2) (CO)_(10) + ` moles of O in `CO_(2)` `7 xx ` moles of `Re_(2)O_(7) + 1 xx `molesof CO `= 10 xx` molesof `Re_(2) (CO)_(10) + 2 xx ` moles of `CO_(2)` or `7a + b = 10 c + 2 d""` . . . (iii) Fromthe eqns . (i),(ii)and (iii) , we get17 a = b i.e., `17 xx ` moles of `Re_(2) O_(7)`= moles of CO `17 xx (2 . 50)/( 484,.4) = ("wt . of CO in G")/(28) [{:(mol. wt. of Re_(2) O_(7) = 484.4),("mol. wt. of CO = 28"):}] ` Wt . of CO = 2 . 46g |
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| 4157. |
Which of the following is used as an antioxidant in food |
| Answer» SOLUTION :BTX is USED in PETROL | |
| 4158. |
Which of the following does not give brick red ppt. with fehling solution ? |
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Answer» Formalin |
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| 4159. |
Whichof the following compound gives a ketone with Grignard reagent ? |
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Answer» Formaldehyde |
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| 4160. |
What is meant by catalyst poison? |
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Answer» Solution :(i) The substances when ADDED to a catalysed REACTION decreases or completely destroys the activity of a catalyst are often KNOWN as CATALYTIC POISONS. (ii) In the reaction `2SO_2 + O_2 to 2SO_3` with Pt catalyst, the catalyst poison is `AS_2O_3` . |
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| 4161. |
What is diazonium salts? |
| Answer» SOLUTION :Ar `N_(2)^(+)X^(-)` is CALLED DIAZONIUM salt, where Ar is an aromatic ring and X may be an ion like `Cl^(-), Br^(-) HSO,_(4)^(-)`. As compound contains two nitrogen atoms `(overset(+)N-=N)` hence the name diazonium salts (di-two, azo nitrogen and onium from ammonium). | |
| 4162. |
Which of the following complex is not hydrate isomer of [Cr(H_(2)O)_(6)]Cl_(3) ? |
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Answer» `[Cr(H_(2)O)_(3)Cl_(3)].3H_(2)O` |
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| 4163. |
Which one of the following is the lightest |
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Answer» 0.2 mole of hydrogen gas Weight of `H_(2)=` moles `xx` molecular wt. `=0.2xx2=0.4 g` (b) `6.023xx10^(23)` REPRESENTS 1 mole Thus `6.023xx10^(22)` will REPRESENT 0.1 mole Wight of `N_(2)=0.1xx28=2.8=2.8 g` (C) Weight of silver `=0.1 g` (d) Weight of oxygen `=32xx0.1=3.2 g` (e) Weight of water `=1 g` Thus, 0.1 g silver is the lightest. |
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| 4164. |
Which of the following thermodynamic varibles is extensive ? |
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Answer» PRESSURE |
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| 4165. |
Which of the following has the maximum number of unpaired d electrons ? |
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Answer» `Ni^(3+)` `Ni^(3+)to1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(0)3d^(7)`
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| 4166. |
Valence bond theory for bonding in transition metal complexes was developed by Pauling. From the valence bond point of view, formation of a complex involves reaction between Lewis bases (ligands) and a Lewis acid (metal atom or metal ion) with the formation of coordination covalent (or dative) bonds between them. The model utilizes hybridization of metal s, p and d valence orbitals to account for the observed structures and magnetic properies of complexes. Valence bond theory is able to deal satisfactorily with many stereo chemical and magnetic properies but is has nothing to say about electronic spectra or the reason for the kinetic inertness of chromium (III)and low spin cobalt (III) octahedral complexes. To understand this and more other features of transition metal we must turn to other theories like crystal field theory etc. Pure crystal field theory assumes that the only interaction between the metal ion and the ligands is an electrostatic or ionic one with the ligands being regarded as negative point charges. This theory is quite successful in interpreting many important properties of complexes. The hybridization of [NiCl_(2)(PPh_(3))_(2)]" and "[NiCl_(2).(Pme_(3))_(2)] are respectively (consider PPh_(3) a bulkier ligand than Pme_(3)) : |
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Answer» `SP^(3)" and "DSP^(2)` |
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| 4167. |
Write the different oxidation states of iron. Why +2 oxidation state of manganes is more stable ? (Zof Mn =25). |
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Answer» Solution :The different oxidiation states of iron are +2 and +3.The atomic number of Mn is `25=1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(2)3d^(5)` In + 2 oxidiation STATE,configuration will be `1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(2)3d^(5)` In +3 oxidation state, configuration will be `1s^(2)2s^(2)2p^(6)3s^(2)3p^(6)4s^(2)3d^(4)` In `3d^(5)` configuration, Mn has half filled d-orbital and half filled and fully filed orbitals are more stable. Also, shielding effect is SMALL and electrons are strongly held by nucleus. The exchange energy of these electrons is very LARGE. Thus +2 oxidation state is more stable. |
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| 4168. |
Two reactions, (i) A to Products, follow first order kinetics. The rate of reaction (i) is doubled when temperature is raised from 300 K to 310 K. The half-life for this reaction at 310 K is 30 minutes. At the same temperature, B decomposes twice as fast as A. If the energy of activation for the reaction for the reaction (ii) is half taht of reaction (i), calculate of reaction (ii) at 300 K. |
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Answer» Solution :Calculation of ACTIVATION energy of REACTION (i) `T_(1)=300" K", T_(2)=310" K",k_(1)=k,k_(2)=2K` `:.""LOG""(k_(2))/(k_(1))=(E_(a))/(2.303" R")((T_(2)-T_(1))/(T_(1)T_(2))), i.e., log2=(E_(a))/(2.303xx8.314)xx(10)/(300xx310)" or "E_(a)=53.60" kJ mol"^(-1)` Calculation of rate constant of reaction (i) at 310 K `k=(0.693)/(t_(1//2))=(0.693)/(30" min")=2.31xx10^(-2)min^(-1)` Rate constant of reaction (ii) at 310 `K=2xx2.31xx10^(-2)min^(-1)=4.62xx10^(-2)min^(-1)` Energy of activation of reaction (ii) `=(53.60" kJ mol"^(-1))/(2)=26.80" kJ mol"^(-1)` Aim. To calculate k for reaction (ii) at 300 K `log""(k_(300" K"))/(k_(300" K"))=(E_(a))/(2.303"R")((T_(2)-T_(1))/(T_(1)T_(2)))` `:.""log""(4.62xx10^(-2))/(k_(300" K"))=(26.80)/(2.303xx8.314xx10^(-3))xx(10)/(300xx310)=0.0151` or `""(4.62xx10^(-2))/(k_(300" K"))="Antilog"0.0151=1.035` or `""k_(300" K")=(4.62xx10^(-2))/(1.035)=4.46xx10^(-2)min^(-1)` |
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| 4169. |
Which of the following is cross linked polymer ? |
| Answer» SOLUTION :Melamine | |
| 4170. |
The vapour pressure of CS_(2) at 50^(@)C is 845 torr and a solution of 2.0 g sulphur in 100g of CS_(2) has a vapour pressure of 845/9 torr. Calculate the formula of sullphur molecule. |
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Answer» Solution :Calculation of molar mas of sulphur. Accoring to RAOULT's law, `(P_(A)^(@)-P_(S))/P_(S)=(W_(B)xxM_(A))/(M_(B)xxW_(A))` `P_(A)^(@)854 TORR, P_(S)848.9 torr, W_(B)=2.0g,` `W_(A)=100 g, M_(A)(CS_(2))=76 g mol^(-1)` `((854torr-848.9torr))/((848.9torr))=((2.0g)xx(76.g mol^(-1)))/(M_(B)xx(100g))` `M_(B)=((2.0g)xx(76.g mol^(-1))xx(848.9 torr))/((5.1 torr)xx(100g))=253.0 mol^(-1)` Calculation of molecular formula of sulphur. LET the formula of sulphur=`S_(N)` `NXX(32g mol^(-1))=253.0 g mol^(-1)` `n=((253g mol^(-1)))/((32g mol^(-1)))=7.9~~8` Thus, the molecular formula of suphur=`S_(8)`. |
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| 4172. |
Which of the following does not react with oxygen directly? Zn, Ti, Pt, Fe |
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Answer» Solution :Platinum is a noble METAL. The sum of its FIRST four ionization enthalpies is very large. Therefore, it does not react with oxygen directly. In contrast Zn, Ti and Fe are active metals and hence directly ract with oxygen to form their RESPECTIVE oxides. `(2 Zn +O_(2) overset(Delta)rarr 2 ZnO, Ti + O_(2)overset(Delta)rarr TiO_(2), 2 Fe + 3O_(2)overset(Delta)rarr 2 Fe_(2)O_(3))` |
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| 4173. |
Whichof the followingis insolubeisdil HCl ? |
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Answer» Aniline |
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| 4174. |
Whch one the following ore is not an ore of Al |
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Answer» Anglesite |
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| 4175. |
What is the nature of an antacid ? |
| Answer» Solution :SUBSTANCES which REDUCE the role of a HCI by preventing the interaction of histamine with the RECEPTOR present in the stomach wall are called antacids. The most commonly used antacids are cimetidine and RANITIDINE | |
| 4176. |
Which of the following option the first compound has less entropy than second: |
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Answer» `(i)` AQUEOUS solution of `1 "M of" MgCI_(2) (II)` aqueous solution of `1 "M of" NaCI` |
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| 4177. |
The unit of rate constant of second order reaction is….. |
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Answer» litre .`"MOL^(-1)","SECOND"^(-1)` |
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| 4178. |
The spin magnetic moment of cobalt in the compound , Hg[Co(SCN)_(4)] is : |
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Answer» `sqrt(3)` |
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| 4179. |
When 6 xx 10^22electrons are used in the electrolysis of a metallic salt, 1.9 gm of the metal is deposited at the cathode. The atomic weight of that metal is 57. So oxidation state of the metal in the salt is |
| Answer» Answer :B | |
| 4180. |
Using IUPAC norms, write the systematic names of the following: [Pt(NH_(3))_(2)Cl(NH_(2)CH_(3))]Cl |
| Answer» SOLUTION :Diamminechlorido(METHYL AMINE)PLATINUM(II) chloride | |
| 4181. |
Which aromatic acid among the following is weaker than simple benzoic acid ? |
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Answer»
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| 4182. |
What is adsorption ? How does adsorption of a gas on a solid surface vary with (a) temperature (b) pressure. Iilustrate with the help of approprite graphs. |
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| 4183. |
Which of the following is not the property of interstitial compound |
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Answer» They have HIGH M.P, HIGHER than those of PURE metals |
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| 4184. |
Zinc is obtained from ZnO by |
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Answer» CARBON reduction |
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| 4185. |
The temperature dependence of the rate of achemical reaction can be accurately explained by Arrhenius equation. With the help of Arrhenius equation, calculate the rate constant for the first order reaction C_2H_5I(g)toC_2H_(4(g))+HI_((G))at700K.Energy of activation (Ea)for the reaction is 209kjmol_(-1)and rate constant at 600K is 1.60xx10^(-5)s^(-1)[Universal gas constant R=8.314JK^(-1)mol^(-1)] |
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Answer» Solution :log `k_2= log(1.60xx10^(-5))+(209xx10^3Jmol^(-3)XX100)/(2.303xx8.314xx600xx700)=(0.204-5)+2.599=-2.197` `therfore k_2`=antilogo-2.197=antilogoof3.803=`6.3535xx10^(-3)s^(-1)` |
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| 4186. |
Which of the following interaction lies in the range of 8-42kH/mol? |
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Answer» `H_(2)..H_(2)O` (b) `H-Cl…H-Cl`Dipole-dipole interaction (van der waal.s force) energy < 8kJ/mol (c) `F^(-)….HF` Ion-dipole H-bond (van der waal.s force) energy < 42kJ/mol (d) `HCN....NH_(3)` H-bond energy ranges from 8-42kJ/mol. |
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| 4187. |
Which of the following ishighly corrosivesalt ? |
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Answer» ` FeCl_2` |
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| 4188. |
The solubility of iodine in water is greately increased by: |
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Answer» ADDING an acid |
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| 4189. |
Which is paramagnetic from the following? Fe^(2+), Zn^(0), Hg^(2+), Ti^(+4) |
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Answer» only `FE^(2+)` |
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| 4190. |
The temporary effect in which there is complete tranfer of a shared pair of pi-electrons to one of the atoms joined by a multiple bond on the demand of an attacking reagent is called |
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Answer» INDUCTIVE effect |
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| 4191. |
What is tonsil ? Write its functions. |
| Answer» SOLUTION :Tetra ETHYL LEAD (TEL). It is WIDELY used as an ANTIKNOCK compound. | |
| 4192. |
Which of the following is characteristic of a carbocation?(i) It can rearrange to a more stable carbocation (ii)It can eliminate a hydride ion to form an alkene. (iii) It can add to an alkene to form a new carbocation. (iv) It can abstract a hydride ion from an alkane. |
| Answer» Answer :(A,B,D) | |
| 4193. |
When 20g of naphtoic acid (C_(11)H_(8)O_(2)) is dissolved in 50g of benzene (K_(f)=1.72 k kg "mol"^(-1)), a freezing point depression of 2K is observed. The van't Haff factor (i) :- |
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Answer» `0.5` |
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| 4194. |
Which allotrope of phosphorus is more reactive and why? |
| Answer» SOLUTION :White PHOSPHORUS is more REACTIVE. This is because it is less stable because of angular strain in `P_4` molecule where the ANGLES are only `60^(@)`. | |
| 4195. |
Valence bond theory for bonding in transition metal complexes was developed by Pauling. From the valence bond point of view, formation of a complex involves reaction between Lewis bases (ligands) and a Lewis acid (metal atom or metal ion) with the formation of coordination covalent (or dative) bonds between them. The model utilizes hybridization of metal s, p and d valence orbitals to account for the observed structures and magnetic properies of complexes. Valence bond theory is able to deal satisfactorily with many stereo chemical and magnetic properies but is has nothing to say about electronic spectra or the reason for the kinetic inertness of chromium (III)and low spin cobalt (III) octahedral complexes. To understand this and more other features of transition metal we must turn to other theories like crystal field theory etc. Pure crystal field theory assumes that the only interaction between the metal ion and the ligands is an electrostatic or ionic one with the ligands being regarded as negative point charges. This theory is quite successful in interpreting many important properties of complexes. Select the correct statement about the crystal field theory. |
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Answer» Metal-ligand bond in COORDINATION compounds arises PURELY from electrostatic interaction between the metal ion and the ligand. |
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| 4196. |
What will be the pH of a solution formed by mixing 40 ml of 0.10 M HCl with 10 ml of 0.45 M NaOH? |
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Answer» 12 |
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| 4197. |
Valence bond theory for bonding in transition metal complexes was developed by Pauling. From the valence bond point of view, formation of a complex involves reaction between Lewis bases (ligands) and a Lewis acid (metal atom or metal ion) with the formation of coordination covalent (or dative) bonds between them. The model utilizes hybridization of metal s, p and d valence orbitals to account for the observed structures and magnetic properies of complexes. Valence bond theory is able to deal satisfactorily with many stereo chemical and magnetic properies but is has nothing to say about electronic spectra or the reason for the kinetic inertness of chromium (III)and low spin cobalt (III) octahedral complexes. To understand this and more other features of transition metal we must turn to other theories like crystal field theory etc. Pure crystal field theory assumes that the only interaction between the metal ion and the ligands is an electrostatic or ionic one with the ligands being regarded as negative point charges. This theory is quite successful in interpreting many important properties of complexes. Which of the following is correct for the complex [Ti(H_(2)O)_(6)]^(3+) ? |
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Answer» Hybridization of CENTRAL metal ion of the complex is `sp^(3)d^(2)`. |
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| 4198. |
Which of the following drug is analgesic and non-narcotic ? |
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Answer» PENICILLIN |
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| 4199. |
Which of the following will be obtained in very small amount during this reaction? CH_(3)-CH=CH-CH_(2)-underset(O)underset(||)C-O-H underset((ii)Br_(2)//"C"Cl_(4),Delta)overset((i)AgOH)rarr"Products" |
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Answer»
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| 4200. |
What product is expected when tertiary butyl bromide is reacted with sodium ethoxide? Why that product is not formed and how that product can be obtained? |
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Answer» Solution :`CH_3-underset(CH_3)underset(|)overset(CH_3)overset(|)(C )-Br+NaOC_2H_5underset(-NaBr)(rarr)CH_3-underset(CH_3)underset(|)overset(CH_3)overset(|)(C )-OC_2H_5` The EXPECTED product is shown above. But the MAJOR product is 2-methyl-1-propene. This is because sodium ethoxide is a STRONG nucleophile as WELL as a strong buse. Thus elimination REACTION predominates over substitution. The product in the reaction can be obtained as `CH_3-underset(CH_3)underset(|)overset(CH_3)overset(|)(C )-Br+NaOC_2H_5underset(-NaBr)(rarr)CH_3-underset(CH_3)underset(|)overset(CH_3)overset(|)(C )-OC_2H_5` |
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