1) For an ideal gas , the fugacity is equal to pressure and ______
Ans. f/p =1
2) Which is the correct unit for entropy?
Ans. J K-1 mol-1
3) The equation for the evaluation of β in M.B. distribution law is
________
Ans. β = 1/kT
4) The expression for homonuclear diatomic molecule in Rotational
partition function is given by ________
Ans. qrot= 2I kT / σ h2
5) ________ deals with the study of chemical reactions which are caused by the absorption of light radiations.
Ans. Photochemistry
6) _____ is the measure of effective concentration of a species in a mixture.
Ans. Activity
7) Mathematical probability always lies between _______.
Ans. 0 and 1
8) The particles obeying Maxwell-Boltzmann statistics are called
_________
Ans. Maxwellons
9) ______ relates the microscopic properties with macroscopic properties.
Ans. Partition function
10) _____ achieves the condition of producing an intense and coherent beam.
Ans. Laser
11) The Boltzmann entropy equation is________
Ans. S = Klnw
12) Striling’s approximation lnN! =__________
Ans. NlnN-N
13) The translational partition function (Qtr) =_______
Ans. [2Î mkT / h2] 3/2. V
14) The electronic partition function of monoatomic gas value is _____
Ans. 1
15) What is the rate for intersystem crossing process?
Ans. KISC [S1]
16) The fugacity coefficient value for an ideal gas________
Ans. 0
17) What is the value of activity of solid in their standard state?
Ans. 1
18) In which of the following process, the process is always non-feasible?
Ans. ΔH > 0, ΔS > 0
19) The entropy of CO at absolute zero is______
Ans.Zero
20) The term used to define the phenomenon of emission of light in a
chemical reaction______
Ans.Chemical luminescence
21) The activities of liquids, solids and liquid solvents in pure state under 1 atm pressure is taken as
Ans. Unity at each temperature
22) The phosphorescence is otherwise known as -------------
Ans. delayed fluorescence
23) Choose the residual entropy for solid N2O
Ans. 5.8 JK-1
24) What is meant by integer partition?
Ans. representing an integer as sum of positive integers
25) How many partitions will be formed for the integer 3?
Ans. 3
26) What is meant by number theory?
Ans. study of integers
27) In an electrolytic cell the electrode at which the electrons enter the solution is called the ______; the chemical change that occurs at this electrode is called _______.
Ans. cathode, reduction
28) Which of the following statements is FALSE?
(a) Oxidation and reduction half-reactions occur at electrodes in electrochemical cells.
(b) All electrochemical reactions involve the transfer of electrons.
(c) Reduction occurs at the cathode.
(d) Oxidation occurs at the anode.
(e) All voltaic (galvanic) cells involve the use of electricity to initiate nonspontaneous chemical reactions.
Ans. (e)
29) The half-reaction that occurs at the anode during the electrolysis of molten sodium bromide is:
Ans. 2 Br→Br2 + 2 e-
30) The best definition of polarisation is ___________
Ans. Electric dipole moment per unit volume
31) What mass (in grams) of nickel could be electroplated from a solution of nickel (II) chloride by a current of 0.25 amperes flowing for 10 hours?
Ans. 2.7 g
32) Molten AlCl3 is electrolyzed for 5.0 hours with a current of 0.40 amperes. Metallic aluminum is produced at one electrode and chlorine gas, Cl2, is produced at the other. How many liters of Cl2 measured at STP are produced when the electrode efficiency is only 65%?
Ans. 0.55 L
33) How long (in hours) must a current of 5.0 amperes be maintained to electroplate 60 g of calcium from molten CaCl2?
Ans. 16 hours
34) How long, in hours, would be required for the electroplating of 78 g of platinum from a solution of [PtCl6]2-, using an average current of 10 amperes at an 80% electrode efficiency?
Ans. 5.4
35) How many faradays are required to reduce 1.00 g of aluminum (III) to the aluminum metal?
Ans. 0.250
36) Which of the following is the strongest oxidizing agent?
Ans. Ag+
37) As the cell given below operates, the strip of silver gains mass (only silver) and the concentration of silver ions in the solution around the silver strip decreases, while the strip of lead loses mass and the
concentration of lead increases in the solution around the lead strip.
Which of the following represents the reaction that occurs at the negative electrode in the above cell?
Pb / Pb(NO3)2 (1.0 M) || AgNO3 (1.0 M) / Ag
Ans. PbPb2+ + 2 e-
38) For a voltaic (or galvanic) cell using Ag, Ag+(1.0 M) and Zn, Zn2+ (1.0 M) half-cells, which of the following statements are incorrect?
Ans. Reduction occurs at the zinc electrode as the cell operates.
39) Consider the standard voltaic (or galvanic) cell: Fe, Fe2+ versus Au, Au3+. Which answer identifies the cathode and gives the Eofor the cell?
Ans. Au, 1.94 V
40) What is the value of E for the half-cell:
MnO4-(0.010 M) + 8H+(0.20 M) + 5e￾Mn2+ (0.020 M) + 4H2O?
Ans. 1.44 V
41) Calculate the potential (in volts) for the voltaic (or galvanic) cell indicated at 25oC.
Ga / Ga3+ (10-6 M) || Ag+(10-4 M) / Ag
Ans. 1.21 V
42) A concentration cell is constructed by placing identical Cu electrodes in two Cu2+ solutions. If the concentrations of the two Cu2+ solutions are 1.0 M and 0.0020 M, calculate the potential of the cell.
Ans. 0.080 V
43) What is Go per mole of dichromate ions for the reduction of dichromate ions,Cr2O72-, to Cr3+ by bromide ions, Br-, in acidic solution? (Hint: Use the standard cell potential.)
Ans. -145 kJ
44) Estimate the equilibrium constant for the system indicated at 25oC.
3 Mg2+ + 2Al → 3Mg + 2Al3+
Ans. ~10-72
45) In voltaic cells, such as those diagrammed in your text, the salt bridge
_______.
Ans. allows charge balance to be maintained in the cell
46) Which of the following statements is (are) true for all voltaic (or galvanic) cells?
(I) Reduction occurs at the cathode.
(II) The anode gains mass during discharge (note: this means operation of the cell.)
(III) The voltage is less than or equal to zero.
Ans. only I
47) In the standard notation for a voltaic cell, the double vertical line "||"represents:
Ans. a salt bridge
48) Which one of the following definitions best describes the concept of work?
Ans. the flow of energy from one body to another through uniform molecular motion
49) An isolated system is best described by which one of the following statements?
Ans. Neither matter nor heat can pass into or out of the system
50) Which one of the following statements describes a path function?
Ans. A property of a system that depends on the path taken between the initial and final states
Post a Comment