Unformatted text preview: trength of collisions between gas molecules and the walls of the vessel containing the gas is the pressure. This is true and is how we calculate the pressure in the kinetic theory of gases. c) To obtain the root mean squared speed of gas molecules in m/s, it is necessary to use the temperature in kelvin, the molar mass in kg/mol and R = 8.3145 J/mol.K. This is true. To measure the speed of molecules in SI units (i.e. in m/s), we need to make sure all quantities involved (M, T and R) are also in SI units. Hence, R should be in J/K.mol, T in K and M in kg/mol). d) For an ideal gas, the quantity α is equal to 1/T. True statement. Indeed, a = (1/V) (∂V/∂T)P = (1/V) x (∂[nRT/P]/∂T)P = (1/V) x (nR/P) = 1/T e) Euler’s chain (or cyclic) rule applied to the state variables X, Y and Z is: (∂X/∂Y)Z (∂Y/∂Z)X (∂Z/∂X)Y =  1 True statement. This is how we characterize the Euler’s rule! f) A, B and C are three different states of a system. If the change in energy ΔUAB from state A to state B is + 10 J and the change in energy ΔUBC from state B to state C is – 20 J, the change in energy ΔUCA from state C to state A is – 10 J. This is an incorrect statement. ΔUAB + ΔUBC = + 10 J + (– 20 J) =  10 J. Furthermore, ΔUAB + ΔUBC = U(B) – U(A) + U(C) – U(B) = U(C) – U(A) = ΔUAC and ΔUCA =  ΔUAC = 10 J (NOT  10 J) 2 Question 5: (5 points) Which among the following statements is correct?...
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 Spring '07
 AREsker
 Physical chemistry, Thermodynamics, pH

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