Advertisements
Advertisements
प्रश्न
Answer the following in one or two sentences.
Comment on the spontaneity of reactions for which ∆H is positive and ∆S is negative.
Advertisements
उत्तर
When ∆H positive and ∆S is negative, then ∆G is positive regardless of temperature. Such reactions are nonspontaneous at all temperatures.
APPEARS IN
संबंधित प्रश्न
Answer the following in one or two sentences.
State whether ΔS is positive, negative or zero for the reaction 2H(g) → H2(g). Explain.
Answer the following in one or two sentences.
State second law of thermodynamics in terms of entropy.
Answer in brief.
What is entropy? Give its units.
For a certain reaction ΔH° = 219 kJ and ΔS° = –21 J/K. Determine whether the reaction is spontaneous or nonspontaneous.
Equilibrium constant for a reaction is 20. What is the value of ΔG° at 300 K? (R = 8 x 10-3 kJ)
A system is changed from an initial state to a final state by a manner such that ∆H = Q. If the change from initial state to final state was made by a different path, then ____________.
Identify the INCORRECT statement.
What is the entropy change (in J K−1 mol−1) when one mole of ice is converted into water at 0°C? (The enthalpy change for the conversion of ice to liquid water is 6.0 kJ mol−1 at 0°C)
Which one of the following has ΔS0 greater than zero?
Heat of combustion of C(s), H2(g) and C2H6(g) are −x1, −x2 and −x3 respectively. Hence heat of formation of C2H6(g) is ____________.
At what temperature, a chemical reaction will have the following values of ∆G, ∆S and ∆H?
∆G = −5.2 KJ mol−1, ∆H = 145.6 kJ mol−1, ∆S = −216 kJ mol−1
The H-H bond energy is 430 kJ mol-1 and Cl-Cl bond energy is 240 kJ mol-1. ΔfH for HCl is - 90 kJ, then H-Cl bond energy is ______.
Relation between ΔH and ΔU for the reaction, \[\ce{2SO_{3(g)} -> 2SO_{2(g)} + O_{2(g)}}\] is _______.
Identify the unit used for measurement of energy according to international system of units?
The criterion for a spontaneous process is ______.
Standard enthalpy and standard entropy changes for the oxidation of ammonia at 298 K are −382.64 kJ mol−1 and −145.6 JK−1 mol−1, respectively. Standard Gibb's energy change for the same reaction at 298 K is ______.
Dinitrogen and dioxygen combined to form nitrous oxide in equilibrium at 850 K. The equilibrium constant for this reaction is 0.56. If the equilibrium concentration of nitrous oxide gas is 3 × 10-3 M and both dinitrogen and dioxygen have the same concentration, then what will be the concentration of dinitrogen gas in M?
Write the correct condition for spontaneity in terms of Gibbs energy.
Identify whether the following pair have larger entropy or not. If yes then Why?
He(g) in a volume of 1 L or He(g) in a volume of 5 L both at 25°C.
Identify whether the following pair have a larger entropy or not. If yes then Why?
O2{g) at 1 atm or O2(g) at 10 atm both at the same temperature.
Write the relationship between Gibbs energy change for a process and total entropy change of system and surroundings.
For a certain reaction ΔH0 is −224 kJ and ΔS0 is −153 J K−1. At what temperature the change over from spontaneous to non-spontaneous will occur?
Calculate ΔG0 for the reaction
\[\ce{CH_{4(g)} + H_{2(g)}-> C2H_{6(g)}}\]
State whether the reaction is spontaneous or not. (Given: KP = 3.358 × 1017, T = 25° C, R = 8.314 × 10−3 kJK−1 moI−1)
Define second law of thermodynamics.
Which of the following is true about the decomposition of ozone?
Change in Gibbs energy for a certain reaction at 300 K is –24 kJ and change in enthalpy is –16 kJ. What is the entropy change of the reaction?
