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
Obtain the relationship between ∆G° of a reaction and the equilibrium constant.
Answer in brief.
What is entropy? Give its units.
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.
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 ____________.
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?
For the following reaction:
\[\ce{Fe2O3_{(s)} + 3CO_{(g)} -> 2Fe_{(s)} + 3CO2_{(g)}}\]; ΔH0 = −29.8 kJ and ΔS0 = 15 J K−1. What is the value of \[\ce{ΔS_{(total)}}\] at 298 K?
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 ______.
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)
Identify the unit used for measurement of energy according to international system of units?
A reaction is spontaneous at low temperatures but non-spontaneous at high temperatures. Which of the following is true for the reaction?
Identify whether the following pair have a larger entropy or not. If yes then Why?
C2H5OH(l) or C2H5OH(g)
What is a spontaneous process? What are its characteristics?
Calculate ΔG for ΔH = − 110 kJ, ΔS = + 40 J K−1 at 400 K.
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?
