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
In which of the following, entropy of the system decreases?
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.
Answer the following question.
Obtain the relation between ΔG and `triangle "S"_"total"`. Comment on the spontaneity of the reaction.
For a certain reaction ΔH° = 219 kJ and ΔS° = –21 J/K. Determine whether the reaction is spontaneous or nonspontaneous.
Answer the following question.
Determine whether the following reaction is spontaneous under standard state conditions.
2H2O(l) + O2(g) → 2H2O2(l)
if ΔH° = 196 kJ, ΔS° = –126 J/K, does it have a cross-over temperature?
One mole of NaCl(s) on melting absorbed 30.5 kJ of heat and its entropy increased by 28.8 J K−1. The melting point of NaCl is ____________.
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.
For a process, entropy change of a system is expressed as ________.
Which one of the following has ΔS0 greater than zero?
Which of the following conditions indicates the reaction is spontaneous?
For a reaction to be non-spontaneous at all temperatures, values of ΔH and ΔS respectively are ____________.
Calculate the amount of heat liberated during formation of 2. 7 kg of water if heat of formation of water is - 284.5 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 ______.
The equilibrium constant for a reaction is 10, value of ΔG° at 300 K is (R = 8 × 10-3 kJ)
For a reaction ΔH = - 30kJ and ΔS = - 45 JK-1, at what temperature reaction changes from spontaneous to non-spontaneous?
When will be change in Gibb's free energy always negative?
Relation between ΔH and ΔU for the reaction, \[\ce{2SO_{3(g)} -> 2SO_{2(g)} + O_{2(g)}}\] is _______.
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 ______.
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?
Which of the following is true about the decomposition of ozone?
