Advertisements
Advertisements
Question
Answer the following in one or two sentences.
State whether ΔS is positive, negative or zero for the reaction 2H(g) → H2(g). Explain.
Advertisements
Solution
ΔS is negative. Two moles of gaseous H atoms are converted into 1 mole of H2 gas. Thus, a disorder of the system decreases, and hence, entropy decreases, or ∆S is negative.
APPEARS IN
RELATED QUESTIONS
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?
Equilibrium constant for a reaction is 20. What is the value of ΔG° at 300 K? (R = 8 x 10-3 kJ)
Identify the INCORRECT statement.
For a process, entropy change of a system is expressed as ________.
For a reversible spontaneous change, ∆S 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)
In which of the following, ∆S is positive?
For the reaction:
\[\ce{2Cl_{(g)} -> Cl2_{(g)}}\]
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?
Equilibrium constant for a reaction is 20. What is the value of ∆G0 at 300 K? (R = 8 × 10−3 kJ)
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
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 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?
In which of the following reaction the value of Kp will be equal to Kc?
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.
What is a spontaneous process? What are its characteristics?
Calculate ΔG for ΔH = − 110 kJ, ΔS = + 40 J K−1 at 400 K.
ΔH for the reaction is − 110 kJ, and ΔS is + 40 JK−1 at 400 K. The free energy change for the reaction is ______.
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?
