For a reaction with ΔH = 100 kJ and ΔS = 200 J/K, at what temperature will the reaction become spontaneous?
Practice Questions
1 question
Q1
For a reaction with ΔH = 100 kJ and ΔS = 200 J/K, at what temperature will the reaction become spontaneous?
500 K
250 K
200 K
100 K
To find the temperature at which the reaction becomes spontaneous, set ΔG = 0: 0 = ΔH - TΔS. Thus, T = ΔH/ΔS = (100,000 J)/(200 J/K) = 500 K.
Questions & Step-by-step Solutions
1 item
Q
Q: For a reaction with ΔH = 100 kJ and ΔS = 200 J/K, at what temperature will the reaction become spontaneous?
Solution: To find the temperature at which the reaction becomes spontaneous, set ΔG = 0: 0 = ΔH - TΔS. Thus, T = ΔH/ΔS = (100,000 J)/(200 J/K) = 500 K.
Steps: 7
Step 1: Understand that for a reaction to be spontaneous, the change in Gibbs free energy (ΔG) must be less than or equal to zero.
Step 2: Recall the formula for Gibbs free energy: ΔG = ΔH - TΔS, where ΔH is the change in enthalpy, T is the temperature in Kelvin, and ΔS is the change in entropy.
Step 3: Set ΔG to 0 to find the temperature at which the reaction becomes spontaneous: 0 = ΔH - TΔS.
Step 4: Rearrange the equation to solve for T: T = ΔH / ΔS.
Step 5: Convert ΔH from kJ to J because ΔS is in J/K. Since ΔH = 100 kJ, multiply by 1000 to get ΔH = 100,000 J.
Step 6: Substitute the values into the equation: T = 100,000 J / 200 J/K.
