General Questions and Answers

Comprehension 3 NaBr used to produce AgBr for use in photography can be self prepared as follows Fe Br FeBt FeB Br Fe Brg Fe Big Na CO3 NaBr CO2 FegO4 Mass of iron required to produce 2 06 x 103 kg NaBr A 420 g B 420 kg ii iii not balanced not balanced 11 C 4 2 x 105 kg D 4 2 108 g If the yield of ii is 60 iii reaction is 70 then mass of iron required to produce 2 06 x 103 kg Nap A 105 kg B 105 g C 10 kg D none

second option in this case with or without selection of any correct op If speed of a wave 2 x 10 m s and valelength 3000 then Frequency 2 x 10 8 Hz Frequency 6 7 x 10 4 Hz Wave number 3 3 106 m Wave number 107 m 1

A glow worm of mass 5 0 g emits red light 650 nm with power of 0 10 W entirely in the backward direction What velocity v in m s will it have accelerated to after 10 years if released in free space and assumed to live Then v is

In aqueous solution Cd II exists as 6 coordinate aqua complex The solution on treatment with Br ion forms finally 4 coordinate Cd II complex with Br ions successively in four steps with stepwise formation constants logK 1 56 logK 0 54 logK 0 06 and logk 0 37 The higher value of K as compared to K is due to A transformation of trigonal complex into tetrahedral complex B change from octahedral to tetrahedral geometry C increase in AH of the reaction D large increase in the number of particles when fourth Br enters the coordination zone

The volume of nitrogen gas at STP required to cover a sample of silica gel with a monomolecular layer is 112 cm g of gel Calculate the surface area per gram in m of the gel if each nitrogen molecule occupies 16 0 x 10 22m Give your answer to the nearest single digit integer NA 6 x 10 3

If all the O atoms from 4 4 g CO 6 022 x 1022 molecules of N O 0 2 moles of CO and 1 12 L of SO gas at NTP are removed and combined to form O gas then the resulting gas occupies a volume of at NTP A 22 4 L B 44 8 L C 33 6 L D 11 2 L

HI cannot be prepared by the action of conc H SO4 on KI because A HI is a stronger acid than H SO4 B HI is more volatile than H SO4 C conc H SO4 is an oxidant and HI is a reductant D conc H SO4 is a dehydrating agent

17 10 pts The mass of a proton neutron and electron is 1 661 x 10 27 Kg 1 662 x 10 27 Kg and 9 11 x 10 31 Kg respectively Calculate the total mass of the ion and the wt of Am protons in the space below

Which of the following represents correctly the changes in thermodynamics properties during the formation of mol of an ideal binary solution A C ve J mol Ok ve ve J mol AGmix AHmix TASmb Mole fraction ve TASmix AGmix AHmix Mole fraction B D AGmix TASmix AHmix Mole fraction ve J mot Ok ve ve J mol Ok ve TASmix AHmix AGmix Mole fraction

139 74 The degree of ionisation of an acid HA is 0 00001 at 0 1 M concentration Its dissociation constant will be a 109 c 10 b 10 11 d 10 7 What will be the ionisation constant of formic acid

Which of the following substances are responsible for slowing down of the rate of autoxidation A Butyl hydroxyl toluene skipped B C Sucralose Saccharin

V Litre of solution A Resistance 50 ohm is mixed with V Litre of solution B V 2 V Resistance 100 ohm Resistance of final solution is 80 ohm then will be using same cell Correct statement out of the following for penicillin is are

Consider the following redox reaction H O AX BY HA YO BX unbalanced It is also known that oxidation number of X is 2 and neither X nor water is involved in the redox process In compound BY B is cation and consider its oxidation number 4 Answer the following questions based on the information given Select the incorrect option The element A is undergoing reduction The element B is undergoing reduction The element B is undergoing oxidation The element Y is undergoing oxidation

A 4 log 2 B 4 log 2 C 10 log 2 D 10 log 2 Ka for HCN is 5 x 10 10 For maintaining a constant pH of 9 the volume of 5 M KCN solution require be added to 10 mL of 2 M HCN solution is A 4 mL B 8 mL 2MB C 2 mL D 10 mL

1 Al OH 2 Zn OH 3 Both together 4 None at all A colourless liquid A b p 184 C is sparingly soluble in warm water to which it gives feebly alkaline On treating with NaNO and dil HC in the cold solution it yields a solution which reacts with an alkaline solution of B naphthol to give an orange yellow precipitate Compound A is 1 C H N CI 2 C H NHNH 3 n C H NH 4 C H NH

Thermal stability of BaCO3 CaCO and MgCO is 1 BaCO CaCO MgCO 3 CaCO MgCO BaCO In metal carbonyls there is 1 No z bond between CO and metal atom 2 BaCO MgCO CaCO 4 MgCO CaCO BaCO

Alejandra just finished making her hydrogen calibration curve Her data is best described by the following equation y 127 4 ln r 715 23 If she observed a line in the helium spectrum that had a scale reading of 2 9 what wavelength would this correspond to If Carmen adds zeros to your answer do not worry It will be graded correctly

Study the data you collected for Trials 1 and 2 When the amplitude increases what happens to the wavelength O The wavelength increases O The wavelength decreases O The wavelength stays the same

The basicity of hydrides of group 15 decreases in the order A NH3 AsH3 SbH3 BiH3 PH3 B C D NH3 PH3 AsH3 SbH3 BiH3 NH3 SbH3 AsH3 BiH3 PH3 BiH SbH AsH3 PH3NH

Holtz had given two equation and are known as Gibbs Helmholtz equation One equation can be expressed in terms of change in free energy AG and enthalpy AH while other can be expressed in terms of change in internal energy AE and work function AW AG AH T d AG dT da000 1 AW AW AE T d 2 dt V Where T is temperature equation 1 is obtained at constant pressure while equation B is obtained at constant volume system It is observed that for the reaction N g 3H g 2NH g Free energy change at 25 C is 33 kJ while at 35 C is 28 kJ which are at a constant pressure 5 What would be the difference between enthalpy change at 25 C and 35 C for a given reaction B 5 kJ C 3 kJ D zero A 4 kJ 6 What would be the free energy change at 30 C A 30 5 kJ B 33 kJ C 28 kJ D 30 5 kJ Internal energy change at 25 C is E while at 35 C is E then 7 A E E B E EFE D

The bond dissociation energies for Ch 12 and IC are 242 3 151 and 211 3kJ mol respectively The enthalpy of sublimation of iodine is 62 8 kJ mol What is the standard enthalpy of formation of ICI g 1 211 3kJ mol 2 14 6 kJ mol 3 16 8 kJ mol 4 33 5 kJ mol

ncorrect statement regarding product of reaction H Br 1 eq Kinetic controlled product is a secondary bromide whereas thermodynamically controlled product is a tertiary bromid Kinetic controlled product is a secondary bromide whereas thermodynamically controlled product is a primary bromi Both kinetic thermodynamic controlled product is secondary bromide Both kinetic thermodynamic controlled product is a tertiary bromide

lon a I II b I III c I II III 35 A complex containing K Pt IV and Cl is 100 ionised giving i 3 Thus complex is a K PtCl c K PtCl b K PtCl d K PtCl 36 Which of the fall d II III a 43 T 19 a C

Calculate the number of equivalents in 10 litre of 0 5 MBa OH solution Ba 137 1 0 1 2 10 3 100 4 I Fac mer isomerism is associated with which one of the following complexes M central met 1 M AA 2 MA B 3 M AA 4 MABCD H Se has higher boiling point than H S This is best explained by

Potassium salt of benzoic acid CH COOK can be made by action of potassium permanganate om toluene as follows CH CH3 KMnO4 CH COOK MnO KOH H O If the yield of potassium benzoate can t realistically be expected to be more than 71 what is the minimum number of grams of toluene needed to acheive this yield while producing 11 5 g of C H COOK

You will appreciate that the ionization enthalpy and atomic radius are closely related properties To understand these trends we have to consider two factors i the attraction of electrons towards the nucleus and ii the repulsion of electrons from each other The effective nuclear charge experienced by a valence electron in an atom will be less than AH kJ mol 550 500 450 400 350 0 60 Li 520 10 Na 496 K 419 Rb 403 20 30 40 Atomic number 2 Cs 374 50 60 3 6 b O of elements of the second period as a

A homodiatomic molecule X have bond order 1 then which of the following prediction s will be correct for The difference of total number of bonding and antibonding e is 2 Molecule can be odd electron molecule Total number of bonding electrons is more than antibonding electrons Last e of X molecule must be entered into bonding molecular orbital

35 36 In which of the following transitions will the wavelength be minimum 1 n 6 ton 4 2 n 4 to n 2 3 n 3 to n 1 4 n 2 to n 1 The increasing order of the rate of HCN addition to compound A Dis

chemist reacted 12 762 grams of sodium with water by heating the product until Il the excess water was removed and only the oxide was left The mass of the xide product was 16 991 grams Calculate the moles of sodium

12 A compound is made by mixing cobalt III nitrite and potassium nitrite solutions in the ratio of 1 3 The aqueous solution of the compound showed 4 particles per molecule whereas molar conductivity reveals the presence of six electrical charges The formula of the compound is a Co NO 2KNO c K Co NO b Co NO 3KNO d K Co NO 4

41 43 44 A Inorganic salt 42 Reddish brown fumes 45 In redox reaction H O2 oxidises K Fe CN 6 into K Fe CO and NO3 ions in acidic medium than how many moles of H2O2 will react with Imole of K Fe CN 1 5 moles 2 9moles 3 8moles 4 30 5moles K Cr O7 conc H SO4 AAJ KA TOPPER Which is correct statement regarding above observation 1 It confirms the presence of Cl ions 2 It confirms the presence of Br ions 3 It confirms the presence of both ions 4 It neither confirms the presence of CT nor Br ions unless it is passed through NaOH solution A buffer solution contains equal concentration of X and HX The k for X is 10 10 The pH of the buffer solution is 1 4 2 7 3 10 4 14 Which of the following drugs is a tranquilizer and sedative 1 Sulphadiazine 2 Papaverine 3 Equanil 4 Mescaline Which one of the following reacts with HBr 1 2 3 H C OH OH CH CH OH OH

1 1 8 10 2 3 6x10 Which is a pair of geometrical isomers CI Br Cl Br H Br H Cl CH Br 3 6 0x10 Br H H CI 4 1 3x10 III 3 II and IV Br 1 II 1 I and II 2 I and III 4 III and IV The temperature of a sample of gas is raised from 127 Cto 527 C The averago kinetic anorm IV CH

Boyle s temperature of a vander Waal s gas is 350 K Which of the following statement s is are correct for the gas A The gas can t be liquefied at 300 K B The gas can be liquefied at 150 K C The gas shows negative deviation at low pressure and 275 K D The gas shows positive deviation at any pressure at 400 K

0 N and O are converted to monocations N and O respectively which is wrong stateme 1 In N the N N bond weakens 2 In O the 0 0 bond order increases 3 In O the paramagnetism decreases 4 N becomes diamagnetic

Study the data you collected for Trials 3 and 4 When the amplitude decreases what happens to the frequency The frequency stays the same O The frequency increases The frequency decreases

13 Match the geometry given in column A with the complex given in column B using the codes given below Column B Column A a Cu NH 2 b Ag NH i Tetrahedral ii Octahedral iii Square planar iv Trigonal bipyramidal Linear c Fe CO d Cr H O e NiC12 V a i e ii d iii a iv c v b b i d ii e iii a iv c v b c i d ii e iii b iv a v c d i c ii e iii h iv a x d

26 In a first order reaction the concentration of reactants decreases from 400mol L to 25 mol L in 200 seconds The rate constant for the reaction is a 1 01386 S 1 b 2 10 S 1 d 3 4 x 10 S c 1 386 x 10 2S 1 reactio C for a first order

1 Given Efe Fe 0 036 V EFe Fe 0 439 V The value of standard electrode potential for the charge Fe aq e Fe aq will be 2 0 385 V 4 0 270 V AIEEE 2009 1 0 072 V 3 0 770 V 271

2 A compound contains C H N only 3 1 gm of this compound gives 4 4 gm of CO on combustion and in ano experiment during estimation of nitrogen 6 2 gm of this compound gives 3 4 gm of NH Find percent composition of compound

Base catalysed condensation between the following compounds followed by dehydration gives methyl vinyl ketone 1 HCHO and CH COCH3 2 HCHO and CH CHO 3 Two molecules of CH3CHO 4 Two molecules of CH COCH

Describe the effect of the following factor whether the increase decrease or has no effect on the actual yield of CaCO3 s in the limiting reactant experiment Using a coarse filter paper instead of one with fine porosity Select one Increase Decrease Has no effect

Match List I with List ll and select the correct answer using codes given below the lists List II Magnetic moment B M List I Metal ions 1 Cr3 2 Fe2 3 Ni2 4 Mn A 35 B 30 C 24 D 15 E 8 1 1 B 2 C 3 E 4 D 3 1 D 2 C 3 E 4 A Which is an incorrect statement 2 1 B 2 C 3 E 4 A 4 1 D 2 E 3 C 4 A AAJ KA TOPPER

H O is prepared in the laboratory when 1 MnO2 is added to dilute cold H SO4 2 BaO is added to CO bubbling through cold water 3 PbO2 is added to an acidified solution of KMnO4 4 Na O is added to boiling water At certain Hill station pure water boils at 99 72 C If Kh for water is 0 513 Ckgmol

What would be the equivalent conductivity of a cell in which 0 5 N salt solution offers a resistance of 40 ohm whose electrodes are 2 cm apart and 5 cm in area 1 10 ohm cm eq 2 3 30 ohm cm ea 4 20 ohm cm eq 25 ohm cm eg ea

The rate constant k for a certain reaction is measured at two different temperatures temperature 275 0 C E 371 0 C Assuming the rate constant obeys the Arrhenius equation calculate the activation energy E for this react Round your answer to 2 significant digits k 2 2 10 4 8 10 kJ x10

A substance when dissolved in water at 10 M concentration absorbs 10 percent of an incident radiation in a path of 1 cm length What should be the concentration of the solution in order to absorb 90 of the incident radiation

3 4 5 The number of moles of iron in a mixture of 144 gms FeO and 320 gms of Fe O3 will be The number of moles of neutrons found in 2 gms of Oxygen atoms will be If from a sample of 160 gms SO 6 023 x 1023 molecules are removed followed by removing 22 41 gas at STP then the mass of the remaining gas will be

The air is a mixture of a number of gases The major components are oxygen and nitrogen with approximate proportion of 20 is to 79 by volume at 298 K The water is in equilibrium with air at a pressure of 10 atm At 298 K if the Henry s law constants for oxygen and nitrogen at 298 K are 3 30 x 107 mm and 6 51 x 107 mm respectively calculate the composition of these gases in water

One mole of magnesium in the vapour state absorbed 1200 kJ mol of energy If the first and second ionization energies of Mg are 750 and 1450 kJ mol 1 respectively the final composition of the mixture is 1 86 Mg 14 Mg 2 36 Mg 64 Mg2 3 69 Mg 31 Mg2 4 31 Mg 69 Mg2

O H O KMnO4 H SO4 MnSO4 H O O2 K SO4 which is correct statement Number of gm equivalent of H O2 and KMnO4 reacts in the ratio of 5 2 Number of moles of MnSO4 and O2 produced in the ratio of 5 2 Equivalent mass of H SO4 is 29 4 100 ml 2 27 V H O2 reacts completely with 160 ml 0 5M KMnO4 in given reaction