Advertisements
Advertisements
Question
Answer the following in one or two sentences.
Comment on the spontaneity of reactions for which ∆H is positive and ∆S is negative.
Advertisements
Solution
When ∆H positive and ∆S is negative, then ∆G is positive regardless of temperature. Such reactions are nonspontaneous at all temperatures.
APPEARS IN
RELATED QUESTIONS
Define entropy.
In which of the following, entropy of the system decreases?
Answer the following question.
Although ΔS for the formation of two moles of water from H2 and O2 is –327J K–1, it is spontaneous. Explain.
(Given ΔH for the reaction is –572 kJ).
Answer the following question.
Obtain the relation between ΔG and `triangle "S"_"total"`. Comment on the spontaneity of the reaction.
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 ____________.
Identify the INCORRECT statement.
For a process, entropy change of a system is expressed as ________.
Arrange the following in order of increasing entropy.
I. 1.0 mol H2O (298 K, 1 atm)
II. 1.0 mol H2O (270 K, 1 atm)
III. 1.0 mol H2O (400 K, 1 atm)
In which of the following, ∆S is positive?
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 ____________.
Which of following is residual entropy of a substance?
Standard molar entropy is ______.
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 ______.
For which of the following reaction, ΔH = ΔU?
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?
In which of the following reaction the value of Kp will be equal to Kc?
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.
Write the relationship between Gibbs energy change for a process and total entropy change of system and surroundings.
ΔH for the reaction is − 110 kJ, and ΔS is + 40 JK−1 at 400 K. The free energy change for the reaction is ______.
Find out the value of equilibrium constant for the following reaction at 298 K, \[\ce{2NH3_{(g)} + CO2_{(g)} ⇌ NH2 - COONH2_{(aq)} + H2O_{(l)}}\] Gibbs Standard energy change 298 K = –13.6 kJ mol−1.
