You're viewing 1 free preview question for Chemistry HL — subscribe to unlock 131 more, plus the Full Question Bank, Mock Papers & Worksheets.Upgrade

Energy Cycles in Reactions · Paper 2 — Free Chemistry HL Practice Questions

1MasterySAQ-SThermochemistry and enthalpy diagrams6 marksPaper 2~9 min
The enthalpy below (not to scale) represents the reaction pathway for the formation of hydrogen iodide: H2(g)+I2(g)→2HI(g)\text{H}_2(\text{g}) + \text{I}_2(\text{g}) \rightarrow 2\text{HI}(\text{g}) The activation energy for the forward reaction is 165 kJ mol−1165\,\text{kJ mol}^{-1} and the enthalpy change for the forward reaction is +9.4 kJ mol−1+9.4\,\text{kJ mol}^{-1}. The reactants are assigned an enthalpy value of 0 kJ mol−10\,\text{kJ mol}^{-1}.
(a)
State the enthalpy values, in kJ mol−1\text{kJ mol}^{-1}, of the products and of the transition state. [2 marks]
(b)
Explain, using collision theory, why increasing the temperature increases the rate of the forward reaction. [2 marks]
(c)
Deduce the activation energy for the reverse reaction and explain whether the reverse reaction is more or less sensitive to a given temperature increase than the forward reaction. [2 marks]
diagram

Solutions

Questions 2-132

Unlock these questions with Premium

Sign Up →

That's every free question here — 1 of 132.

+131 more questions, plus Mock Papers & Worksheets, are waiting in Premium.

Upgrade