Chemistry2 Nhsas Series 1 2024
Chemistry2 Nhsas Series 1 2024
Chemistry2 Nhsas Series 1 2024
autonomous systems
Exercise-1 :
Define the following terms: thermodynamic system, system boundary, open, closed and isolated
system , Intensive quantities, extensive quantities, state variable , state function, transformation,
equilibrium (thermal, dynamic, chemical).
Exercise-2*
Classify the following sets into:
a) Open systems, b) closed systems d) isolated systems
Exercise-3:
Classify the following quantities into intensive and extensive:
Pressure, volume, concentration, temperature, number of moles, density, density,
normality, mass, energy.
Exercise-4 *
Given the function F(x,y) = x2y+3xy
a) calculate thetotal differential dF of this function?
b) Show that dF is an ETD.
c) Calculate the integral of dF between A(0.0) and B(1,1) according to the following 3 paths:
Path-1: y=x, Path-2: y= x2, path-3: from A(0,0) to C(0,1) and from C(0,1) to B(1,1), Conclude.
Exercice-5
The state equation for real gases (Van Der Walls) is given by: (P+an2/ V2)(V-nb)=nRT.
Express P as a function of T and V and calculate the partial derivatives: (𝜕𝑃/𝜕𝑉)T and (𝜕 2P/∂V2)T
exercise-6
we consider the following differential equation: dF=x2ydx+(x3/3)dy
a) show that dF is an ETD
b) We go from the initial state A (0,0) to the final state B (1,1) by three paths
Path-1: during this transformation y=x
Path-2 during this transformation y=x2
Path-3 we first go from A(0,0) to C(1,0) then from C(1,0) to B(1,1)
Calculate the integral of dF for each path and conclude.
Exercice-7** The state equation of an ideal gas is PV=nRT , demonstrate the following equalities
(∂P/∂V)T (∂V/∂P)T = 1 and (∂P/∂V)T (∂V/∂T)P (∂T/∂P)V= -1
Exercice-8*
A B
1) What is the final air pressure in the containers? What is the mass of air that was
Transferred from one container to another?
(Intensive variables are uniform, including molecular density and pressure)
Deduce the final quantities of material n(A)final and n(B)final in each container.
Answer : m ( B A) = 26, 1 g et Pf = 22, 5 bars = 22, 2 atm. Data : 1 atm = 76 cmHg = 1, 013x105 Pa.
Exercice-9 A) We consider two cylinders with rigid walls containing one oxygen and the other
nitrogen under the following conditions:
O2 : P1= 10 atm , V1 = 5 litres T1 = 0 0C
N2 : P2= 30 bars , V2 = 0.02 m3 T2 = 353 K
Calculate the masses of O2 and N2 contained in each cylinder
B) We heat the two cylinders up to T= 400 K, calculate the pressure in each cylinder?
C) We connect the two cylinders by a tube fitted with a tap (the volume of the tube is negligible), we
open the tap; What is going on ?
Calculate the total pressure and partial pressure of each gas?
Exercice-10* The real gas equation of state (Van Der Walls (VDW)) is given by:
2 2
(P+an / V )(V-nb)= nRT ( a,b constants characteristic of the gas).
For carbon dioxide (CO2), the coefficients a and b of the Van der Waals equation of state have the
respective values a= 0, 366 kg.m5 .s-2 mol-2 and b= 4, 29.10-5 m3 .mol-1 .
Two moles of this gas are placed in an enclosure of volume V = 1 L at the temperature T = 300 K.
compare the pressures given by the state equations of an ideal gas and VDW gas
the measured value is P = 38, 5 bars.
Answer : ( IG : P= 49.9 bars , VDWG : P= 39.9 bars , at high pressure the ideal gas law is not valide).