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Chemistry · THERMODYNAMICS
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Chemistry · THERMODYNAMICS
During the complete combustion of butane, \( \text{C}_4\text{H}_{10}(g) + \frac{13}{2}\text{O}_2(g) \rightarrow 4\text{CO}_2(g) + 5\text{H}_2\text{O}(l) \), \( 2658.0\text{ kJ} \) of heat is released per mole. How much heat is released when \( 14.5\text{ g} \) of butane gas (molar mass = \( 58\text{ g mol}^{-1} \)) is burned completely at standard conditions?
Read answer →Chemistry · THERMODYNAMICS
Which of the following conditions represents the exact state where \( \Delta H = \Delta U \) for a chemical reaction involving gases?
Read answer →Chemistry · THERMODYNAMICS
A chemical reaction is carried out in a closed vessel made of copper. Which type of thermodynamic system does this setup represent?
Read answer →Chemistry · THERMODYNAMICS
Consider the following thermodynamic properties: (A) Volume (B) Temperature (C) Density (D) Enthalpy (E) Pressure Which of the above are intensive properties? Which of the above statements is/are correct?
Read answer →Chemistry · THERMODYNAMICS
For the ionization process \( \text{M}(g) \rightarrow \text{M}^+(g) + e^- \), the value of \( C_p \) for each species is \( \frac{5}{2}R \). At a temperature \( T = 300\text{ K} \), if the ionization energy \( E_0 \) at \( 0\text{ K} \) is \( 490\text{ kJ mol}^{-1} \), what is the ionization enthalpy \( \Delta_i H^\ominus \) at \( 300\text{ K} \)? (Take \( R = 8.314\text{ J K}^{-1}\text{mol}^{-1} \))
Read answer →Chemistry · THERMODYNAMICS
An ideal gas expands from \( 2\text{ L} \) to \( 10\text{ L} \) against a constant external pressure of \( 1\text{ atm} \) at \( 25^\circ\text{C} \). The amount of heat absorbed by the system from the surroundings is:
Read answer →Chemistry · THERMODYNAMICS
At dynamic chemical equilibrium for the reaction \( A + B \rightleftharpoons C + D \), what is the criterion for the Gibbs energy of the reacting mixture?
Read answer →Chemistry · THERMODYNAMICS
Given below are two statements: Statement I: Enthalpy of solution of a substance at infinite dilution is the enthalpy change when dissolved in an infinite amount of solvent such that interactions between ions are negligible. Statement II: The enthalpy of dilution of a solution is always independent of the initial concentration of the solution. In the light of the above statements, choose the most appropriate answer from the options given below:
Read answer →Chemistry · THERMODYNAMICS
During a single-step compression of a gas by a constant external pressure \( p_{\text{ex}} \), the volume changes from \( V_i \) to \( V_f \). The expression for work done on the system is:
Read answer →Chemistry · THERMODYNAMICS
Match List-I with List-II: List-I (Enthalpy Term) List-II (Defining Equation / Characteristic) A Lattice Enthalpy I \( \text{HCl}\cdot 25\text{ aq.} + 15\text{ aq.} \rightarrow \text{HCl}\cdot 40\text{ aq.} \) B Enthalpy of Atomization II \( \text{Na}(s) \rightarrow \text{Na}(g) \) C Enthalpy of Solution III \( \Delta_{\text{sol}} H^\ominus = \Delta_{\text{lattice}} H^\ominus + \Delta_{\text{hyd}} H^\ominus \) D Enthalpy of Dilution IV \( \text{MX}(s) \rightarrow \text{M}^+(g) + \text{X}^-(g) \) Choose the correct answer from the options given below:
Read answer →Chemistry · THERMODYNAMICS
For one mole of an ideal gas, the molar heat capacity at constant pressure (\( C_p \)) is greater than the molar heat capacity at constant volume (\( C_v \)) by \( R \) primarily because:
Read answer →Chemistry · THERMODYNAMICS
For the combustion reaction \( \text{C}(\text{graphite}) + \text{O}_2(g) \rightarrow \text{CO}_2(g) \) at 298 K, which of the following expressions correctly relates the enthalpy of reaction (\( \Delta H \)) and the internal energy change (\( \Delta U \))?
Read answer →Chemistry · THERMODYNAMICS
In a bomb calorimeter having heat capacity \( 20.7\text{ kJ K}^{-1} \), 2.40 g of graphite is completely burnt in excess oxygen at 298 K according to \( \text{C}(\text{graphite}) + \text{O}_2(g) \rightarrow \text{CO}_2(g) \). Given that the internal energy change for combustion of graphite is \( -2.48 \times 10^2\text{ kJ mol}^{-1} \), the rise in temperature of the calorimeter is:
Read answer →Chemistry · THERMODYNAMICS
A sample of \( 0.5\text{ mol} \) of an ideal gas expands into an evacuated chamber of volume \( 20\text{ L} \) from an initial volume of \( 5\text{ L} \) at \( 300\text{ K} \). Subsequently, \( 150\text{ J} \) of work is done on the gas while compressing it back to \( 10\text{ L} \) at constant volume, and \( 50\text{ J} \) of heat is removed. What is the overall change in internal energy (\( \Delta U \))?
Read answer →Chemistry · THERMODYNAMICS
Given below are statements regarding thermochemical conventions and Hess's Law: (A) By convention, the standard enthalpy of formation (\( \Delta_f H^\ominus \)) of an element in its most stable reference state is taken as zero. (B) Diamond is taken as the reference standard state of carbon with \( \Delta_f H^\ominus = 0 \). (C) Reversing a chemical equation changes the sign of its reaction enthalpy (\( \Delta_r H^\ominus \)) while keeping the numerical magnitude identical. (D) Enthalpy change is an intensive property because it does not depend on the stoichiometric coefficients of the balanced equation. Which of the above statements are correct?
Read answer →Chemistry · THERMODYNAMICS
Consider the formation of ammonia: \( \frac{1}{2}\text{N}_2(g) + \frac{3}{2}\text{H}_2(g) \rightarrow \text{NH}_3(g) \); \( \Delta_r H^\ominus = -46.1\text{ kJ mol}^{-1} \). What is the enthalpy change accompanying the complete decomposition of \( 68\text{ g} \) of gaseous ammonia into its constituent elements at the same conditions?
Read answer →Chemistry · THERMODYNAMICS
Match List-I with List-II: List-I (Substance) List-II (\( \Delta_f H^\ominus / \text{kJ mol}^{-1} \) at 298 K) A \( \text{CO}_2(g) \) I \( -393.51 \) B \( \text{CH}_4(g) \) II \( -74.81 \) C \( \text{C}(\text{diamond}) \) III \( +1.89 \) D \( \text{H}_2\text{O}(l) \) IV \( -285.83 \) Choose the correct answer from the options given below:
Read answer →Chemistry · THERMODYNAMICS
Refer to the bomb calorimeter apparatus shown in the figure used for combustion reactions. Under what operational condition does this calorimetric measurement proceed, and which thermodynamic quantity is directly measured?
Read answer →Chemistry · THERMODYNAMICS
Given below are two statements:\n Statement I: During free expansion of an ideal gas into a vacuum, the work done is maximum.\n Statement II: For isothermal free expansion of an ideal gas, the change in internal energy is zero (\( \Delta U = 0 \)). \nIn the light of the above statements, choose the most appropriate answer from the options given below:
Read answer →Chemistry · THERMODYNAMICS
A gas cylinder fitted with a frictionless piston contains an ideal gas. If the gas is compressed from \( 12.0\text{ L} \) to \( 4.0\text{ L} \) against a constant external pressure of \( 3.0\text{ atm} \), and simultaneously loses \( 1.2\text{ kJ} \) of heat to the surroundings, calculate \( \Delta U \) for the process. (Take \( 1\text{ L}\cdot\text{atm} = 101.3\text{ J} \))
Read answer →Chemistry · THERMODYNAMICS
The Gibbs function \( G \) is defined as \( G = H - TS \). In terms of thermodynamic property classifications, the Gibbs function is:
Read answer →Chemistry · THERMODYNAMICS
At constant pressure and temperature, the entropy change of the surroundings is related to the system's enthalpy change by which expression?
Read answer →Chemistry · THERMODYNAMICS
