For a reaction with ΔH = 100 kJ and ΔS = 200 J/K, at what temperature will the r
Practice Questions
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
Questions & Step-by-Step Solutions
For a reaction with ΔH = 100 kJ and ΔS = 200 J/K, at what temperature will the reaction become spontaneous?
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.
Step 7: Calculate the temperature: T = 500 K.
Gibbs Free Energy – Understanding the relationship between enthalpy (ΔH), entropy (ΔS), and temperature (T) in determining spontaneity of a reaction.
Spontaneity of Reactions – Recognizing that a reaction is spontaneous when ΔG < 0, and calculating the temperature at which ΔG = 0.