Open Question
The reaction H2(g) + I2(g) ⇌ 2 HI(g) has ∆H = -2.2 kcal/mol (-9.2 kJ/mol). Will the equilibrium concentration of HI increase or decrease whenH2 is removed?
7. Energy, Rate and Equilibrium
Le Chatelier's Principle
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The following data was collected for the following reaction at equilibrium
2 A (g) + 3 B (g) ⇌ C (g)
At 25 oC K is 5.2 x 10-4 and at 50 oC K is 1.7 x 10-7. Which of the following statements is true?
a) The reaction is exothermic.
b) The reaction is endothermic.
c) The enthalpy change, ΔH, is equal to zero.
d) Not enough information is given.
A
The reaction is exothermic.
B
The reaction is endothermic.
C
The enthalpy change, ΔH, is equal to zero.
D
Not enough information is given.
Verified step by step guidance1
Identify the relationship between temperature and the equilibrium constant (K). As temperature increases from 25°C to 50°C, the equilibrium constant K decreases from 5.2 x 10^-4 to 1.7 x 10^-7.
Recall Le Chatelier's Principle, which states that if a system at equilibrium is subjected to a change in temperature, the system will adjust to counteract that change. For an exothermic reaction, increasing temperature shifts the equilibrium to favor the reactants, decreasing K.
For an endothermic reaction, increasing temperature shifts the equilibrium to favor the products, increasing K. Since K decreases with increasing temperature, the reaction is likely exothermic.
Consider the options: a) The reaction is exothermic, b) The reaction is endothermic, c) The enthalpy change, ΔH, is equal to zero, d) Not enough information is given.
Based on the analysis, the correct statement is that the reaction is exothermic, as the decrease in K with increasing temperature suggests the reaction releases heat.
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