Physical Chemistry Questions

20 mintue What mass of Ni is deposited at the cathode A current of 3 7A is passed for 6hrs between Ni electrodes in 0 5L of 2M solution of Ni NO3 2 What will be the molarity of solution at the end of electrolysis NICE

Amongst the following the pair having both the metals in their highest oxidation state is A B Fe CN 6 and Co CN 6 CrO Cl and MnO C TiO3 and MnO D MnCh and NiF6 2

For the chemical reaction shown here N2 g The following data was obtained at time 0 sec N 0 60 M H 2 0 M N 0 40 M H M What is the concentration of H at 25 seconds at time 25 sec O There is There is There is There is 1 4 M H at 25 seconds 1 1 M of H 0 60 M of H at 25 seconds at 25 seconds 1 8 M of H at 25 seconds 3 H g 2 NH3 g NH3 0 0 M NH3 M

A constant current of 30 A is passed through an aqueous solution of NaCl for a time of 1 0 hr How many grams of NaOH are produced What is volume of Cl gas at 1 atm 273K produced in litre If 0 224 litra II

In a face centered lattice of X and Y X atoms are presen at the corners while Y atoms are at face centers The the formula of the compound would be if one of the atoms is missing from a corner in each unit cell 1 X Y 24 3 XY 24 2 X24Y7 4 X 4 Y

dt dt KA Select the incorrect order for given properties a AB AB A B L E Charge of B 2 b Na CO K CO Rb CO CS CO Thermal stability c MgF CaF SrF BaF BeF Solubility d LiOH NaOH KOH RbOH CSOH Solubility and stability 1 a b 2 a d 3 only d 4 None 3 70 f a b c d 1 2 3

Assume 96500 C as one unit of electricity If cost of electricity of producing x gm Al is Rs x v is the cost of electricity of producing x gm Mg Chromium metal con ho plated out from on aidia olution containing CrO according to follo

A solution of Ni NO3 is electrolysed between platinum electrodes using a current of 5 ampere for 20 mintue What mass of Ni is deposited at the cathode Ni electrodes in 0 51 of 2M solution of Ni NO

8 a a Equinormal Solutions of two weak acids HA pK 3 and HB pK 5 are each placed in contact with equal pressure of hydrogen electrode at 25 C When a cell is constructed by interconnecting them through a salt bridge find the emf of the cell 500ml water 0 5m mol of aniline K 10 9 and 50mmol of HCI

In a cubic lattice atom X occupies the corn ers of the cube and atom Y occupies the en d centred positions and Z occupies the edg e centres of the cube What will be the simplest formula of the unit cell if one of the face diagonals containing end centre atom is removed

Mock Test 1 for 2 The number of OH ion in 1 mL of solution having pH 4 is 62 pH 4 and face 1 mL OH 1 10 1 10 2 10 10 2 10 10 3 6 02 x 100 4 6 02 10 3 6 02 1010 4 6 02 10 An alkyl bromide X reacts with Na to form 4 563

An organic compound X decomposes following two parallel first 2 order reactions with K K 1 5 and K 1 5 104 min The reaction is allowed to start with only X for 770 minutes K A B K 2 C Identify the correct statements The ratio of C to A at t 770 minutes is 5 6 The ratio of B to A at t 770 minutes is 2 3 Half life of the overall reaction is 770 minutes At t 770 minutes A B C

After electrolysis of NaCl solution with inert electrodes for a certain period of time 600 mL of the solution was left Which was found to be IN in NaOH During the same time 31 75 g of Cu wa deposited in the copper voltameter in series with the electrolytic cell Calculate the percentage yie of NaOH obtained

69 For the reaction 2A B C D the following kinetic data 69 sf4f 2A B were obtained in three separate experiments all at 298 K si fa Initial Concentration Initial 3 K A B dt Concentration A 0 1 M 0 1 M 0 2 M 0 1M The rate law for the formation of Cis 1 k A B B 0 1M 0 2M 4 2 k A B dt dc Initial rate of Formation of C moll s K A 1 2x10 1 2x10 2 4x103 dt 70 Select the incorrect order for given properties f T A 0 1 M 0 1 M 0 2 M dc 1 K AB dt dc 3 K A B dt 70 fed f

Electro chemistry The electrosynthesis of MnO is carried out from a solution of MnSO4 in H SO4 aq If a current of 25 5 ampere is used with a current efficiency of 85 how long would it take to produce 1 kg of MnO

Given electrode potentials Fiely 4 m Fe e aq aq E for the cell reaction Fe E 0 771 volts aq aq aq 2Fe 21 2Fe I A 2 x 0 771 0 536 1 006 volts C 0 771 0 536 0 235 volts 1 2e21 E 0 536 volts Go SPP SOP Ording tot anode Cathode is B 0 771 0 5 x 0 536 0 503 volts D 0 536 0 771 0 235 volts

Which of the following property is widely used to determin the molar masses of proteins Relative lowering in vapour pressure Elevation in boiling point Depression in freezing point Osmotic pressure

3 The equilibrium constant for the reaction Sr s Mg 2 aq Sr 2 aq Mg s is 4 x 10 2 at 25 C The E for a cell made up of the Sr Sr 2 and Mg 2 Mg half cells log 2 0 3 A 0 3717 V B 0 7434 V C 0 1858 V D 0 135

Be 4 Li Be B C N O 50 If 2s 2p mixing is not present then which amon the following is are paramagnetic 1 C 2 B 3 N 4 All of these 51 For linear shape an atom should have

Chromium metal can be plated out from an acidic solution containing CrO according to following equation CrO aq 6H aq 6e Cr s 3H O Calculate i How many grams of chromium will be plated out by 24125 coulombs and ii How long will it take to plate out 1 5 gm of chromium by using 12 5 ampere current

A ii and iii 4 If A Go of the cell reaction D i and iv AgCl s 2H g Ag s H Clis 21 52 KJ then AG of 2AgCl s H g 2Ag s 2H 20 is A 21 52 KJ B 10 76 KJ C 43 04 KJ B ii and iv C i and iii D 43 04 KJ

3 From the following E values of half cells i A e A ED 0 24 V ii B e B E 1 25 V E 1 25 V iv D 2e D E 0 68 V iii C 2e C What combination of two half cells would result in a cell with the largest potential A ii and iii B ii and iv C i and iii D i and iv

Total number of species present in 1 mole of potash alum in terms of avagadro number N are 1 3N 2 5N 3 8N 4 32N Hol reacts with K

In the Kjeldahl s method of estimation of nitrogen NH3 evolved from 0 25 g of organic compound neutralized 50 mL of 0 2 M HCI The percentage of nitrogen in the organic compound is 1 28 2 56 3 67 4 72

ong 2 A metal is known to form fluoride MF When 10A of electricity is passed through a molten salt for 330 sec 1 95g of metal is deposited Find the atomic weight of M What will be the quantity of electricity required to deposit the same mass of Cu from CuSO Colution with inert electrodes for a certain period of time 600 mL of the Was

57 The final product C obtained in this reaction NH CH3 would be 1 3 NH CH3 NH CH3 Ac 0 A COCH 3 Br Br CH3COOH 4 COCH3 CH3 B CH H 0 C H Br NHCOCH3 Br 58 Chemical leaching is useful in the concentration of

1 E Ni Ni 0 25 volt E Au Au 1 50 volt The standard emf of the voltaic cell 3 NiNi 1 0 M Au 1 0 M Au is aq s B 1 75 volt aq A 1 25 volt C 1 75 volt D 4 0 volt

4 25 The desity of NH OH solution is found to be 0 6 g mL It contains 35 by mass of NH OH The normality of the solution is 1 4 8 N 2 10 N 3 0 5 N 4 6 0 N 4 25 61 NH OH faci40 6 g mLIF NH OH a fac 1 4 8 N 2 10 N 3 0 5 N 4 6 0 N

1 N O 2 N O 3 NO 4 0 How many moles of magnesium phosphate Mg PO will contain 0 25 mole of oxygen atoms 1 3 125 10 2 1 25 10 3 25 10 4 0 02 of molecules present in 1 12 10 cc of a gas at STP is

Consider the change in oxidation state of Bromine corresponding to different emf values as shown in the diagram below BrO 1 82 V BrO 1 BrQ 1 5 V HBrO Br 1 0652 V Br 1 595 V Then the species undergoing disproportionation is NEET 2018 2 BrQ

I 2 4 Can t predict 7 The specific conductance of a 0 1 N KCI solution at 23 C is 0 012 ohm cm The resistance of cell containing the solution at the same temperature was found to be 55 ohm The cell constant will be 1 0 142 cm 1 3 0 918 cm 1 2 0 66 cm 1 4 1 12 cm 1 wer Pusa Road New Delhi 110005 Ph 011 4762345

In the following mixtures of acid and bases a 100 mL of 1MHCl 100 mL of 0 5MCa OH 2 b 100 mL of 1MNaOH 100 mL of 0 5H SO4 c 100 mL of 1MNH OH 100 mL of 1MHCI d 100 mL of 1MNaOH 100 mL of 1CH3COOH Neutral solutions are A B C D a and b c and d a and d all of these

How many mL of a 0 175 M FeCl solution are needed to make 250 mL of a solution that is 0 300 M in CH ion A 0 429 mL B 143 mL C 429 mL D It is not possible to make a more concentrated solution from a less concentrated solution igit

82 Which of the following is a buffer solution a 500 mL of 0 1 N CH3COOH 500 mL of 0 1 N NaOH b 500 mL of 0 1 N CH3COOH 500 mL of 0 1 N HCl c 500 mL of 0 1 N CH3COOH 500 mL of 0 2 N NaOH d 500 mL of 0 2 N CH3COOH 500 mL of 0 1 N NaOH NGOL is added to 20 mi of 03 MCH COOH

A radioactive substance A decays 20 in 12 minutes The kinetics of radioactive disintegration of the same substance A is observed using 1 gm of it Choose the correct conclusions drawn from the observations made Use log2 0 3 log 5 0 7 In2 0 69 Inx 2 3 logx Half life of the radioactive substance A 36 minutes The time required for its 60 decay 48 minutes Mass of radioactive substance A left after 180 minutes 31 25 mg Decay constant of the radioactive substance A 3 85 10 2 min

13 An oxide of nitrogen has a molecular weight 92 Find the total number of electrons in one gram mole of that oxide 1 4 6N 2 46N 3 23N 4 2 3N 14 Total number of species present in 1 mole of notash alum in terms of avagadro number N

D 2 02 c 2 30 80 Approximate pH of 0 01 M NaHA is calculated by K 106 and K 108 are ionization constants of H A pKa log C a pH 7 b pH 7 2 PK pH a aj 2 PK 2 a2 pKa 2 d None of these d 2 50 log C 2

86 What is the pH of a solution of 0 28 M acid and 0 84 M of its conjugate base if the ionization constant of acid is 4 x 10 4 a 3 88 b 3 34 c 7 d 10 12 87 The toxic compound 2 4 dinitrophenol has K 104 In an experiment a buffer solution

1 Zn 2 NH 4 NH3 3 MnO The amount of Cu deposited when 10 A of curren is passed for 10 minute through CuSO4 aq is 1 1 97 g 2 2 89 g 3 4 g 4 3 5 g The volume of O g released by 1 C electricity

9 56 c 8 96 d 9 26 84 H CO3 NaHCO 3 found in blood helps in maintaining pH of the blood close to 7 4 An exce of acid entering the blood stream is removed by a HCO3 b H CO3 d CO ion 85 100 mL of 0 02 M benzoic acid nk c H ion

b 3 4 75 What will be the pH and a degree of hydrolysis respectively for the salt BA of 0 1 M concentration Given K for HA 10 6 and K for BOH 106 a a 5 1 7 10 c 9 0 01 d 7 0 01 6 The percentage degree of hydrolysis of a salt of weak acid HA and weak base BOH in its

57 It is found that in 11 2L at 0 C and 1 atm of any gaseous compound of X there is never less than 15 5 gm of X It is also found that 11 2 L of vapours of X at 0 C and 1 atm weighs 62 gm The atomicity of X is

4 molecules of CO 55 Calculate the AHO of N H g if B E N N 159 kJ mol B E H H 436 kJ mol B E N N 941 kJ mot B E N H 398 kJ mol 1 711 kJ mol 3 98 kJ mol 2 62 kJ mol 4 711kJ mol 1

1 g atom of an a emitting XA half life 10 hr was placed in sealed containers 4 52 10 Helium atoms will accumulate in the container after A 4 52 hr C 9 40 hr B 10 00 hr D 20 00 hr

1 05 2 03 9 How many moles of magnesium phosphate Mg PO will contain 0 25 mole of oxygen atoms 1 3 125x10 2 1 25 10 3 2 5 10 4 0 02

In a sample of wood the reading of the wood sample observed from the instrument is 45 dpm and in fresh sample of a tree it is 165 dpm In the absence of wood sample the instrument shows the reading of 5 dpm Identify the correct statement s 1 2 of C14 of C 4 6000 years 100 2 1 6 The age of the wood sample is 9000 years The age of the wood sample is 12000 years If the age of the wood sample is 4000 years the reading shown by instrument would by 100 dpm If the age of the wood sample is 4000 years the reading shown by instrument would be 105 dpm

1 H PO4 is a weak triprotic acid approximate pH of 0 1 M Na HPO4 aq is calculated by d pK pK a2 c pK PK 3 42 0 pK PK2 b pK a PK 3 Which of the following is a buffer solution

a 5 1 7 10 c 9 0 01 76 The percentage degree of hydrolysis of a salt of weak acid HA and weak base BOH in its 0 1 M solution is found to be 10 If the molarity of the solution is 0 05 M the percentage hydrolysis of the salt should be b 10 a 5 c 20 7 What is the hydronium ion concentration of a 0 02 M solution of Cu 2 None of these solution of copper II

2 The standard electrode potential E values of Al AI Ag Ag K K and Cr Cr are 1 66 V 0 80 V 2 93 V and 0 74 V respectively The correc decreasing order of reducing power of the metal is NEET 2019 Odisha 2 Ag Cr AI K 1 Al K Ag Cr

3 The volume of O g released by 1 C electricity a NTP would be 1 5 6 L 5 6 2 96500 11 2 22 4 3 4 96500 96500 The value of specific conductivity is maximum L L