Physical Chemistry Questions

The hardness of water sample containing 2 x 10 3 g of CaCO3 dissolved in 1 L of water is expressed as 20 ppm 2 ppm 200 ppm hr 0 2 ppm

16 NO required for a reaction is produced by the decomposition of N O5 in CCl4 as per the equation 2N2O5 g 4NO2 g O2 g The initial concentration of N O5 is 3 00 mol L and it is 2 75 mol L after 30 minutes The rate of formation of No is a 1 667 10 2 mol L min b 4 167 10 mol L min c 2 083 10 3 mol L min d 8 33 10 3 mol L min April 2019

Unit of Kc for the equilibrium 4 NH3 g 5 O g 4 NO g 6 H O g is mol L 1 L mol 1 mol5 L 5 L5 mol 5

The wavenumbers of the three normal modes of H O are 3656 7 cm 1594 8 cm and 3755 8 cm Evaluate the vibrational partition function at 1500 K

If A H for the reaction N 3 H 2 NH3 is a then A H fo 1 3 NH3 N2 H is the reaction NH3 a a N BIN 2 2 a

The enthalpy changes at 298 K in successive breaking of O H bonds of H O Hare H OH g H O OH H O g The bond enthalpy of the O H bond is 11492 1 498 kJ mol 2 463 kJ mol 1 101 AH 498 kJ mol AH 428 kJ mol 3 428 kJ mol 4 70 kJ mot

PROBLEM 414 Carbondioxide gas from a steel cylinder is bubbled for some time through pure water placed in a jar When the supply of gas is terminated pH of the solution was found to be 3 83 What is the pressure of gas in the cylinder if Henery s constant of CO is 2 3 x 102 For CO K 4 2 x 107 and K 4 8 10 1

1 5 M aqueous solution of acetic acid in water has density 0 9 g mL The molality of the solution will be 1 51 molal 1 02 molal 2 01 molal 1 85 molal

The following equilibrium for the dissociation of oxide of nitrogen are given with its Ke at T C 2NO g N g 20 g Kc 6 7 10 6 2N O5 9 2NO g 2N O g 2N g O g Kc 10 1 Which of the following oxide is most stable according to the given K values NO 2N g 50 g Kc 1023 N g O g Kc 2 102

Which one of the following statements regarding helium is incorrect is used to fill gas balloons instead of hydrogen because it is lighter and non inflammable 2 It is used as a cryogenic agent for carrying out experiments at low temperatures 3 It is used to produce and sustain powerful superconducting magnets 4 It is used in gas cooled nuclear reactors

Use Hess s law to calculate AG rxnusing the following information NO g O g NO2 g AG rxn 2 03 g 3 O2 g 02 g 2 0 g NO g O3 g NO2 g O2 g AG rxn 489 6 kJ AG rxn 463 4 kJ AG rxn 199 5 kJ

If 4g of oxygen diffuse through a very narrow hole how much hydrogen would have diffused under identical conditions 1 16 g 2 1 g 3 1 4 g 4 64 g 4 rough the

N g reacts with H g in either of the following ways depending upon supply of H g N g H g N H 1 N g 2H g N H g If 5LN g and 3 LH g are taken initially at same temperature and pressure Calculate the concentration in volume after the reaction in L

NEET II 2016 1 The percentage of pyridine C5H5N that forms pyridinium ion C5H5NH in a 0 10 M aqueous pyridine solution K for C5H5N 1 7 x 10 9 L 1 0 77 3 0 0060 2 1 6 0 ALL

5 180 The number of atoms per unit cell in a simple cubic bcc an fcc unit cell respectively are 1 4 8 2 4 1 1 4 2 Mark for Review 1 2 4

Select the incorrect statement For solid liquid equilibrium there is only one temperature at 1 atm at which both the phases can coexist Vapour pressure depends on temperature For dissolution of solids in liquids the solubility is constant at a given temperature For dissolution of gases in liquids the concentration of a gas in liquid is independent to the pressure of the gas over the liquid

d trigonal A solid AB has the Bions arranged as below If the A ions occupy half of the tetrahedral sites in the structure The formula of solid is a AB c A B We L b AB2 d A3 B 4 f forroelectric compound

Common ion effect will observed in the aqueous solution of NaCl HCI NaCl CH3COOH CH3COONa NaOH CH3COOH HCI

Which of the following characteristic property is not associated with crystalline solids Sharp melting point Diffused and irregular edges Definite enthalpy of fusion Long range ordered arrangement

Que 7 In a hypothetical reaction A B taking place at constant temperature and pressure activation energies for forward and backward reactions are 15 and 9 kJ mole respectively If potential energy of A is 10 kJ mol then select correct statement Enthalpy of reaction is 6 kJ Potential energy of B is 16 kJ mole Threshold energy of reaction is 24 kJ Reaction is exothermic

Which of the following reactions occur at the cathode during the charging of lead storage battery 1 PbSO4 s 2e Pb s SO 4 2 Pb SO 3 Pb Pb 2e 1 PbSO 2H O PhQ 4H SO 2e SO PbSO4

4 The partial pressure of nitrogen in air is 0 76 atm and its Henry s law constant is 7 6 x 10 atm at 300K What is the molefraction of nitrogen gas in the solution obtained when air is bubbled through water at 300K a 1 x 104 b 1 x 10 c 2 10 d 1 10

One mole of gas occupying 3 litre volume is expanded against a constant external pressure of one atm to a volume of 15 litre The work done by the system is 1 1 215 x 10 J 2 12 15 x 10 3 J 3 121 5 x 10 J par nad lover 4 1 215 x 10 J

Calculate the average A B bond energy in AB4 g AH for AB4 g 74 9 kJ mol AH for A g 155 3 kJ mo AH for B g 188 8 kJ mol AH for A2 g 0 kJ mol AH for B g 0 kJ mol Enter a number in kJ mol to 1 decimal place

If enthalpy of combustion of C s H g and C H6 g are x y and z kJ mol respectively then enthalpy of formation of ethane will be Ox y z Oz x y Oz 2x 3y 31 M

Solubility of AgCl in 0 1 M aqueous NaCl solution is Ksp fo AgCl 1 2 x 10 101 1 x 10 5 M 1 2 10 M 1 2 x 10 5 M 10 M

Ta tify the correct statement a vapour pressure of solution is higher than that of pure solvent b boiling point of solvent is lower than that of solution c osmotic pressure of solution is lower than that of solvent d osmosis is a colligative property

9 A hypothetical electrochemical cell is shown below A A xM B M B The e m f measured is 0 20 V The cell reaction is AIPMT 2006 a The cell reaction cannot be predicted b A B A B c A BA B d A e A B B

If an element X crystallises in bcc arrangement whose edge length equal to 400 pm then the radius of atoms X i 3 1 73 173 pm 149 pm 17 3 pm

Que 20 An ideal gas is expanded by given thermodynamic process with same initial state to same final volume Which of the following is correct order of magnitude of work for given process 1 PV K 11 PV 2 K V II IV III I I II IV III III PV K3 IV PV K4

cooled to 3 534 C What weight of ice would be separated out at this temperature K H O 1 86 K mol kg f 1 352 98 gm 2 252 98 gm 3 302 98 am

4 Consider the equilibrium system involving the oxidation of sulfur dioxide 2SO2 g 102 g 2SO3 g AH 192 kJ Sketch on the graph below with the given equilibrium concentrations the effect of a an increase in SO2 at t 1T b the addition of neon inert gas at t2 1T c a decrease in temperature at t3 1T CONC SO 0 SO TIME

An drug organic compound which described as a pain relief medication is consist of 15 51 Oxygen 75 69 Carbon and 8 80 Hydrogen by mass Estimate the empirical formula of this drug C6H90 C7H902 C13H180 None of them O C13H1802 O C7H90

Enthalpies of combustion of propane butane and pentane are 2220 2878 3537 kJ mol respectively Order of calorific value per gram of fuel will be 1 Propane Butane Pentane 2 Butane Pentane Propane

In a compound atoms of element A forms ccp lattice and atoms of element B occupy of the octahedral voids and 8 WIN of the tetrahedral voids the formula of the compound wi 3 be A B3 A3B5 hr min A3B4 AB2

The wave function of any hydrogen like specie for the orbital 2s is given by 4 2s 1 2 2 z 0 x 2 ao 3 2 3 1 587 A where Zr ao a is 0 529 Hence the radius for nodal surface of 2s orbital for Het is given by 1 0 529 xe 3 2 2 1 058 0 829 4

The correct order of bond length of Si O P O S O and C1 O in SiOH POH SOH2 CIOH Answer A Your Attempt Correct answer CIOH SOH POH SiOH B SiOH4 POH SOH CIOH POH SiOH4 1 SOH CIOH Rat

c 14 d 3 114 Graphite is a soft solid lubricant extremely difficult to melt The reason for this anomalous behaviour is that graphite a is a non crystalline substance b is an allotropic form of diamond c has molecules of variable molecular masses like d has carbon atoms arranged in large plates of rings of strongly bound carbon atoms with weak interplate bonds

A mixture of 9 22 moles of A 10 11 moles of B and 27 83 moles of C is placed in one liter container at a certain temperature The reaction is allowed to reach equilibrium At equilibrium the number of moles of B is 18 32 Calculate the equilibrium constant for the reaction A g 2B g 3C g

7 The solubility product of a salt having general formula MX2 in water is 4 x 10 12 The concentration of M ions in the aqueous solution of the salt is 2005 a 4 0 10 10 M b 1 6 10 4 M e 1 0 10 4 M d 2 0 10 6 M

4 At equilibrium a 0 100 M solution of Acetic Acid contains the following concentrations HC2H3O2 aq H aq C2H302 aq 0 0990 M 1 33x10 3 M 1 33x10 3 M Please calculate the equilibrium constant Keq

18 gram of glucose dissolved in 90 gram of water If the vapour pressure of water at room temperture 25 5 torr What will be the vapour pressure of solution at same temperature 1 25 torr 20 torr 3 18 torr 15 torr 2 4

4 Some of the following gases are soluble in water due to formation of their ions 1 00 II NHs III HCI IV CH4 V H2 Water insoluble gases can be A LIV V B I V C I II III D IV V portial pressure is

2 a b c The acid dissociation constants for sulfurous acid are Kat 1 2 x 10 and K 6 6 x 10 Calculate the pH of a solution of 0 10 M H SO Calculate the pH of a solution of 0 10 M Na SO Calculate the pH of the solution resulting when equal volumes of the soluti

The total vapour pressure of a 8 mol solution of NH3 g in water at 300 K is 100 torr The vapour pressure of pure water is 20 torr at 300 K Applying Henry s law for solute and Raoult s law for solvent The total vapour pressure of 10 mol solution of NH3 g in water at 300 K is 120 Torr 118 Torr 98 Torr

b Hide hint for Question 19 If you need to write N N PJ

Which of the following statements is correct for the non ideal solutions Select one a Activity coefficient is less than one means that the solute finds the vapor more suitable environment than that of an ideal solution under the same condition b Activity coefficient is more than one means that the solute finds the solution more suitable environment than that of an ideal solution under the same condition c Activity coefficient is less than one means that the solute finds the solution more suitable environment than that of an ideal solution under the same condition d Activity coefficient is more than one means that the solute finds the solution more suitable environment than that of an ideal solution under the same condition

PRN 1171814889 NOTE SCREENSHOT PROHIBITED System of review measures A B C Testing of raw material Testing of intermediates

a Calculate The molarity of 400 ml of solution that is prepared by dissolving 34 8 gram K2SO4 salt K2SO4 174 10p b The density of 41 by mass Na3PO4 solution is 0 8 g ml Na3PO4 164 i Find the molar concentration of NasPO4 solution 5p ii Find the total ion concentration of Na3PO4 solution 5p

What is the maximum concentration of equimolar solutions of FeSO4 and Na S so that when mixed in equal volumes there is no precipitation of FeS Ksp of FeS 6 25 x 10 18 1 2 5 x 10 M 3 5 x 10 18 M 2 5 x 10 8 M 4 5 x 10 9 M