CHM201: Physical Chemistry Ii TMA4 Question and Answer

Question 1 : The molar heat capacity of Al is 24.4 J/mol/. How much heat energy is required to heat 100 g of Al from 20  to 80 ? (Al = 27)
A. 5422 J
B. 30000 J
C. 146000 J
D. 813000 J

 

Question 2 : One mole of an ideal gas is heated at a constant pressure of 101300 N , from 273.2 K to 373 K. Calculate the work involved R = 8.314 J/mol/K).
A. 8.314 J/mol
B. 831.4 J/mol
C. 83.14 J/mol
D. 8314 J/mol

 

Question 3 : The specific heat of silver is 0.0565 . Assuming no loss of heat to the surroundings or to the container, calculate the final temperature when 100 g of silver at 40  is immersed in 60 g of water at 10 .
A. 12.6
B. 21.6 .
C. 25
D. 16.2

 

Question 4 : A Brønsted-Lowry base is defined as a substance that
A. increases [H+] when placed in water.
B. decreases [H+] when placed in water.
C. acts as a proton acceptor.
D. acts as a proton donor.

 

Question 5 : The first law of thermodynamics deals with
A. thermodynamic equivalence
B. entropy
C. conservation of energy
D. absolute zero temperature.

 

Question 6 : In the following reaction, which is a Brønsted-Lowry base? 
A.
B.
C.
D. None of these

 

Question 7 : A substance that is capable of acting as both an acid and as a base is _____.
A. Binary acid-base
B. Amphoteric
C. Diprotic
D. conjugated

Question 8 : The common-ion effect
A. increases solubility
B. promotes evaporation.
C. promotes condensation
D. reduces ionization.

Question 9 : Calculate the  value of the reaction: values for HCl,  and  are -92.30, -80.29 and -314.4 respectively
A. 141.8
B. 252.88
C. -141.8
D. -486.99

Question 10 : A Brønsted-Lowry acid is defined as a substance that ______ .
A. acts as a proton acceptor
B. increases [OH�?? ] when dissolved in water
C. acts as a proton donor
D. decreases [H3O+] when dissolved in water

Question 11 : If a gas absorbs 1000 J of heat and expands by 0.5  against a constant pressure of 4 atms (1 atm = 100000 Pa), then the change in internal energy is approximately
A. -1200 J
B. 800 J
C. 1200 J
D. -800 J

Question 12 : The magnitude of  indicates that __________.
A. water autoionizes very quickly
B. water autoionizes very slowly
C. water autoionizes only to a very small extent
D. the autoionization of water is exothermic

Question 13 : Which of these is true of an isochoric system?
A. Takes place at constant temperature
B. Heat is allowed into the system but not allowed out of the system
C. Volume remains constant
D. Pressure is not constant

Question 14 : Which of the following expressions is associated with the law of conservation of energy?
A. dG = dH �?? TdS
B. H = E + PV
C. dE = q + w
D. q = mCdT

Question 15 : For the following reaction, which of the following is a conjugate acid-base pair?  +   (aq) + (aq)
A.  and
B.  and
C.  and
D.  and

Question 16 : Which of these is incorrect about the pH of a solution?
A. The higher the pH, the more acidic the solution is
B. an alkali has a higher pH value than an acid
C. pH = -log
D. It is a measure of the acidity of the solution

Question 17 : Which of these followings would lead to an increase in the internal energy of a system?
A. Adiabatic expansion of the system
B. Work done on the system
C. Work done by the system
D. Loss of heat from the system

Question 18 : For the following reaction, which of the following is a conjugate acid-base pair? 
A. None of the above
B.  and
C. HPO42- and NH4+
D.  and

Question 19 : What is the conjugate base of ?
A.
B.
C. OH^{-}
D.

Question 20 : Which of the following statements about enthalpy is incorrect?
A.  is the enthalpy change at constant pressure
B. enthalpy is a state function
C. Reactions which absorb heat have a positive DH
D. Enthalpy and internal energy of a system are always identical