# CBSE Questions for Class 11 Medical Chemistry Thermodynamics Quiz 1 - MCQExams.com

 A chemical reaction is spontaneous at 298 K but non-spontaneous at 350 K. Which one of the following is true for the reaction?
• $$\Delta G\quad \Delta H\quad \Delta S\\ -\quad \quad -\quad \quad +$$
• $$\Delta G\quad \Delta H\quad \Delta S\\ +\quad \quad +\quad \quad +$$
• $$\Delta G\quad \Delta H\quad \Delta S\\ -\quad \quad +\quad \quad -$$
• $$\Delta G\quad \Delta H\quad \Delta S\\ +\quad \quad -\quad \quad +$$
• $$\Delta G\quad \Delta H\quad \Delta S\\ -\quad \quad -\quad \quad -$$
 Which of the following statements regarding Gibb's energy change is correct?
• If $$\Delta$$G is negative (< 0), the process is non-spontaneous.
• If $$\Delta$$G is positive (> 0), the process is non-spontaneous.
• If $$\Delta$$G is negative (< 0), the process is spontaneous.
• If $$\Delta$$G is positive (> 0), the process is equilibrium.
 $$\triangle H$$ = - 336.2 kcal. What is the value of $$\triangle U$$ approximately at 300 K for the same reaction (R = 2 cal $$degre{ e }^{ -1 }$$ $$mo{ l }^{ -1 }$$)?
• - 320.0 kcal
• - 335.0 kcal
• - 337.2 kcal
• - 353.0 kcal
 Properties of substances like pressure, temperature and density, in thermodynamic coordinates are
• path function
• point function
• cyclic function
• real function
 The INCORRECT match in the following is :
• $$\Delta G^0 < 0,K< 1$$
• $$\Delta G^0 < 0,K= 1$$
• $$\Delta G^0 > 0,K< 1$$
• $$\Delta G^0 < 0,K> 1$$
 Which of the following property is not a thermodynamic property of the system?
• pressure
• temperature
• specific volume
• heat
 Which heat depends on the direction of current?
• Joule heat
• Peltier heat
• Thompson effect
• None of these
 An ideal gas undergoes a cyclic process as shown in Figure.$$\Delta U_{BC}=-5$$ kJ $$mol^{-1}$$, $$q_{AB}=2$$ kJ $$mol^{-1}$$$$W_{AB}=-5$$ kJ $$mol^{-1}$$, $$W_{CA}=3$$ kJ $$mol^{-1}$$Heat absorbed by the system during process CA is:
• $$+18$$ kJ $$mol^{-1}$$
• $$-18$$ kJ $$mol^{-1}$$
• $$-5$$ kJ $$mol^{-1}$$
• $$+5$$ kJ $$mol^{-1}$$
 The combustions of benzene (l) gives $$CO_2(g)$$ and $$H_2O(l)$$. Given that heat of combustion of benzene at constant volume is $$-3263.9 \ kJ\, mol^{-1}$$ at $$25^oC$$, heat of combustion (in $$kJ\,mol^{-1}$$) of benzene at constant pressure will be:$$(R =8.314JK^{-1}\,mol^{-1})$$
• $$+3260$$
• $$-3267.6$$
• $$+4152.6$$
• $$-452.46$$
 The standard Gibbs energy for the given cell reaction in $$kJ$$ $${mol}^{-1}$$ at $$298K$$ is:$$Zn(s)+{Cu}^{2+}(aq)\rightarrow {Zn}^{2+}(aq)+Cu(s)$$$${E}^{o}_{cell}=2V$$ at $$298K$$(Faraday's constant, $$F=96000\ C{mol}^{-1}$$)
• $$-384$$
• $$-192$$
• $$192$$
• $$384$$
 A process will be spontaneous to all temperatures if:
• $$\Delta H > 0$$ and $$\Delta S < 0$$
• $$\Delta H < 0$$ and $$\Delta S > 0$$
• $$\Delta H > 0$$ and $$\Delta S > 0$$
• $$\Delta H < 0$$ and $$\Delta S < 0$$
 Compute the heat of formation of liquid methyl alcohol (in kJ mol $$^{ -1 }$$) using the following data. The heat of vaporisation of liquid methyl alcohol is 38  kJ mol$$^{ -1 }$$. The heat of formation of gaseous atoms from the elements in their standard states: $$H =$$ 218  kJ mol$$^{ -1 }$$., $$C = 715$$  kJ mol$$^{ -1 }$$. , $$O = 249$$  kJ mol$$^{ -1 }$$. Average bond energies:$$C-H = 415$$  kJ mol$$^{ -1 }$$. $$C-O = 356$$ kJ mol$$^{ -1 }$$. $$O-H = 463$$  kJ mol$$^{ -1 }$$.
• $$\Delta H = -266$$ kJ mol$$^{ -1 }$$.
• $$\Delta H = +266$$ kJ mol$$^{ -1 }$$.
• $$\Delta H = -190$$ kJ mol$$^{ -1 }$$.
• None of these
 For the process :   $$\\ \mathrm{H}_{2}\mathrm{O}(l)$$ ($$1$$ bar, $$373$$ $$\mathrm{K}$$) $$\rightleftharpoons \mathrm{H}_{2}\mathrm{O}(\mathrm{g})$$ ( $$1$$ bar, $$373 \mathrm{K}$$), the correct set of thermodynamic parameters is
• $$\Delta \mathrm{G}=0,\Delta \mathrm{S}=+ ve$$
• $$\Delta \mathrm{G}=0, \Delta S=-ve$$
• $$\Delta \mathrm{G}=+ve, \Delta \mathrm{S}=0$$
• $$\Delta \mathrm{G}=- ve, \Delta \mathrm{S}=+ ve$$
 A gas mixture consists of $$2$$ moles of $$O_2$$ and $$4$$ moles of Ar at temperature $$T$$. Neglecting all vibrational modes, the total internal energy of the system is
• 11 RT
• 4 RT
• 15 RT
• 9 RT
 For a given reaction, $$\triangle H = 35.5\ kJmol^{-1}$$ and $$\triangle S = 83.6\ JK^{-1} mol^{-1}$$. The reaction is spontaneous at: (Assume that $$\triangle H$$ and $$\triangle S$$ do not vary with temperature)
• $$T > 298\ K$$
• $$T < 425\ K$$
• $$T > 425\ K$$
• All temperatures
 The following two reactions are known $$Fe_2O_{3(s)} + 3CO_{(g)}\rightarrow 2Fe(s) + 3CO_{2(g)}$$ ; $$\Delta \ H = -26.8\ kJ$$$$FeO_{(s)} + CO_{(g)}\rightarrow Fe_{(s)} + CO_{2(g)}\Delta H = -16.5\ kJ$$The value of $$\Delta\ H$$ for the following reaction is:$$Fe_2O_{3(s)} + CO_{(g)}\rightarrow 2FeO_{(s)} + CO_{2(g)}$$
• + 10.3 kJ
• - 43.3 kJ
• - 10.3 kJ
• + 6.2 kJ
 Which of the following is the property of a system
• pressure and temperature
• internal energy
• volume and density
• all of the above
 Consider the following processes:                                                  $$\Delta H\left({kJ}/{mol}\right)$$$$\dfrac{1}{2} A \rightarrow B$$                               $$+150$$$$3B \rightarrow 2C + D$$                       $$-125$$$$E + A \rightarrow 2D$$                          $$+350$$For $$B + D \rightarrow E + 2C, \Delta H$$ will be:
• $$525\ {kJ}/{mol}$$
• $$-175\ {kJ}/{mol}$$
• $$-325\ {kJ}/{mol}$$
• $$325\ {kJ}/{mol}$$
 One mole of an ideal diatomic gas undergoes a transition from A to B along a path AB as shown in the figure, The change in internal energy of the gas during the transition is:
• $$20\ J$$
• $$-12\ kJ$$
• $$20\ kJ$$
• $$-20\ kJ$$
 For the reaction, $$X_2O_4(i)\rightarrow 2XO_2(g)$$, $$\Delta U=2.1k cal, \Delta s=20 cal K^{-1}$$ at 300 K. Hence, $$\Delta G$$ is:
• 2.7 k cal
• -2.7 k cal
• 9.3 k cal
• -9.3 kcal
• Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• Assertion is correct but Reason is incorrect
• Both Assertion and Reason are incorrect
 The thermal motion means
• motion due to heat engine
• disorderly motion of the body as a whole
• motion of the body that generates heat
• random motion of molecules
 Assertion (A) : Zeroth law of thermodynamics gives us the concept of energyReason (R) : Internal energy is dependent on temperature
• 1) Both Assertion and Reason are true and reason is correct explanation of Assertion
• 2) Both Assertion and Reason are true but reason is not correct explanation of Assertion
• 3) Assertion is true but reason is false
• 4) Assertion is false but reason is true
 Internal energy per mole of gas depends on
• viscosity
• density
• temperature
• thermal conductivity
 The internal energy of an isolated system :
• remains constant
• keeps on changing
• zero
• may change depending on gas
 The laws of thermodynamics speak about
• rates of chemical changes
• feasibility and energy transformations of a

process
• Both the rate and energy changes of a process
• Energy changes in chemical reactions only
 The internal energy of a perfect gas depends on :
• Pressure
• Temperature
• Volume
• Specific heat
 The internal energy of an ideal gas depends upon
• only its pressure
• only its volume
• only its temperature
• its pressure and volume
 Internal energy does not include
• vibrational energy
• rotational energy
• energy arising by gravitational pull
• nuclear energy
 Which of the following is not a thermodynamic coordinate?
• Gas constant (R)
• Pressure (P)
• Volume (V)
• Temperature (T)
 Gas constant $$(R)$$ equals to
• $$\dfrac{C_p}{C_v}$$
• $$1$$
• $$C_v-C_p$$
• $$C_p-C_v$$
 $$C_v$$ for ammonia gas is $$(in J \ mol^{-1} \ K^{-1})$$
• $$29.0$$
• $$12.5$$
• $$20.7$$
• $$31.2$$
 The heat change in a chemical reaction at constant volume is given by:
• $$\Delta H$$
• $$\Delta E$$
• $$\Delta T$$
• $$\Delta V$$
 At the boiling point of water the saturated vapour pressure will be (in mm of Hg)
• 750
• 760
• 850
• 860
 $$10\ g$$ of liquid at $$300\ K$$ is heated to $$350\ K$$. The liquid absorbs $$6\ kcals$$. What is the specific heat of the liquid (in $$cal/g\ ^o C$$)?
• $$6$$
• $$12$$
• $$60$$
• $$120$$
 Joule's experiment converts
• work into heat
• work into electricity
• heat into work
• electricity into work
 What describes a spontaneous reaction?
• Positive $$\Delta H$$
• Negative $$\Delta H$$
• Positive $$\Delta G$$
• Negative $$\Delta G$$
 The temperature at the bottom of a high water fall is higher than that at the top because
• by itself heat flows from higher to lower temperature
• the difference in height causes a difference in pressure
• thermal energy is transformed into mechanical energy
• mechanical energy is transformed into thermal energy
 Therm is the unit of
• heat
• temperature
• thermometry
• work
 Combustion is
• exothermic reaction
• endothermic reaction
• None of these
 Which one of the following is not a thermodynamical co-ordinate?
• $$V$$
• $$R$$
• $$T$$
• $$P$$
 Fill in the blank. Thermodynamics is the branch of science concerned with ____ and ________ and their relation to energy and work.
• heat, temperature
• temperature, pressure
• heat, volume
• volume, pressure
 Identify the incorrect statement ?
• Energy can be converted into matter
• Matter can be converted into energy
• Energy can be converted into matter, and matter can be converted into energy
• Matter can be converted into energy, but energy cannot be converted into matter
• Energy can be measured in units of joules and calories
 If there were no atmosphere, the average temperature on earth surface would be
• lower
• higher
• same
• $${{0}^{o}}C$$
 Mixture of ice and water is form a
• closed system
• open system
• isolated system
• heterogeneous system
 Free energy change for the process $$A(s)\rightleftharpoons B(l)$$ will be:
• 0
• 1
• 2
• 3
 $$\Delta U^{ \ominus }$$ of combustion of methane is $$-X kJ mol^{-1}$$ The value of $$\Delta H^{ \ominus }$$ is
• $$= \Delta U^{ \ominus }$$
• $$> \Delta U^{ \ominus }$$
• $$< \Delta U^{ \ominus }$$
• $$0$$
 The internal energy of compressed real gas, as  compared to that of the ideal gas at the same temperature is
• less
• more
• sometimes less, sometimes more
• maximum
 The internal energy of a perfect gas is :
• completely kinetic
• completely potential
• sum of potential and kinetic energy of the molecules
• difference of kinetic and potential energy of the molecules
 Which of the following process is non-spontaneous?
• Heat flow from hot end to cool end.
• Water flow from higher level to lower level.
• Gas flow from lower pressure region to higher pressure region.
• Gas flow from higher pressure region to lower pressure region.