DP Chemistry Questionbank

• Syllabus

Topic 15: Energetics/thermochemistry

Sub sections and their related questions

15.1 Energy cycles

• 15M.1.hl.TZ2.17: What is the correct order for increasing lattice enthalpy? A.    ...
• 15M.2.hl.TZ1.6g: Determine the standard enthalpy change of formation, \(\Delta H_{\text{f}}^\Theta \), of NaCl(s),...
• 14M.1.hl.TZ1.16: What is the correct definition of lattice enthalpy? A.     Enthalpy change when one mole of a...
• 14M.1.hl.TZ2.16: Which equation represents the lattice enthalpy of calcium chloride? A.    ...
• 14M.1.hl.TZ2.18: Which equation represents the second electron affinity of oxygen? A.    ...
• 14M.2.hl.TZ2.8c: Although magnesium is usually found as \({\text{M}}{{\text{g}}^{2 + }}\) in its compounds, it is...
• 14M.2.hl.TZ2.8d: Consider the lattice enthalpies of \({\text{Mg}}{{\text{F}}_{\text{2}}}\),...
• 14N.1.hl.TZ0.17: The Born-Haber cycle for the formation of magnesium oxide is shown below. What is a correct...
• 14N.1.hl.TZ0.18: Consider the values of \(\Delta {H^\Theta }\) and \(\Delta {S^\Theta }\) À for the reaction of...
• 13N.1.hl.TZ0.17: Which ionic compound has the most endothermic lattice enthalpy? A.     Sodium chloride B.   ...
• 13M.1.hl.TZ1.16: Which combination of ions will give the greatest absolute lattice enthalpy? A.     A small...
• 13M.1.hl.TZ2.18: Which compound has the most positive lattice enthalpy of dissociation? A.     NaCl B.    ...
• 10N.1.hl.TZ0.17: Which is a correct definition of lattice enthalpy? A.     It is the enthalpy change that occurs...
• 10N.2.hl.TZ0.4c: (i)     Identify the enthalpy changes labelled by I and V in the cycle. (ii)     Use the...
• 09N.1.hl.TZ0.17: Which ionic compound has the most endothermic lattice enthalpy? A.     NaCl B.     KCl C.   ...
• 09N.2.hl.TZ0.7a.i: Identify the processes represented by A, B and D in the cycle.
• 09N.2.hl.TZ0.7a.ii: Define the enthalpy change, F.
• 09N.2.hl.TZ0.7a.iii: Determine the value of the enthalpy change, E.
• 09N.2.hl.TZ0.7a.iv: Define the enthalpy change C for the first value. Explain why the second value is significantly...
• 09N.2.hl.TZ0.7a.v: The inter-ionic distance between the ions in NaF is very similar to that between the ions in MgO....
• 09M.2.hl.TZ1.6b.i: State the names for the enthalpy changes c and d.
• 09M.2.hl.TZ1.6b.ii: Deduce which two of the enthalpy changes a to e have negative signs.
• 09M.2.hl.TZ1.6b.iv: Explain why the quantitative value for the lattice enthalpy of calcium bromide is larger than the...
• 09M.1.hl.TZ2.19: Which step(s) is/are endothermic in the Born-Haber cycle for the formation of LiCl? A.    ...
• 11M.1.hl.TZ1.19: Which equation corresponds to the lattice enthalpy for silver iodide, AgI? A.    ...
• 11M.1.hl.TZ2.16: Which ionic compound has the greatest lattice enthalpy? A.     MgO B.     CaO C.     NaF D. ...
• 11M.1.hl.TZ2.18: Which change will not increase the entropy of a system? A.     Increasing the temperature B.   ...
• 12M.1.hl.TZ2.16: Which equation represents the electron affinity of chlorine? A.    ...
• 12M.2.hl.TZ2.3a: The experimental lattice enthalpies of the chlorides of lithium, LiCl, sodium, NaCl, potassium,...
• 12M.2.hl.TZ2.3b: Explain why magnesium chloride, \({\text{MgC}}{{\text{l}}_{\text{2}}}\), has a much greater...
• 12M.2.hl.TZ2.3c: (i)     Identify the process labelled a on the Born–Haber cycle for the determination of the...
• 11N.1.hl.TZ0.17: Which row of the table correctly represents the equations for the lattice enthalpy of substance...
• 16M.1.hl.TZ0.18: Which transition represents an enthalpy of...
• 16M.2.hl.TZ0.4a: (i) State why you would expect tin(II) chloride to have a similar lattice enthalpy to strontium...
• 16N.1.hl.TZ0.18: Which represents the enthalpy change of hydration of the chloride ion?
• 16N.1.hl.TZ0.19: Which ionic compound has the largest value of lattice enthalpy? A. MgS B. MgO C. CaBr2 D. NaF
• 17M.1.hl.TZ1.16: Which equation represents enthalpy of hydration? A.     Na(g) → Na+(aq) + e− B.     Na+(g) →...
• 17M.1.hl.TZ2.16: The Born-Haber cycle for potassium oxide is shown below: Which expression represents the...
• 17M.1.hl.TZ2.17: Which ion’s hydration energy is the most exothermic? A.     Li+ B.     Na+ C.     Br– D.     I–
• 17N.1.hl.TZ0.15: Which statements are correct for ionic compounds? I.   Lattice energy increases as ionic radii...
• 17N.1.hl.TZ0.18: Which equation represents the lattice enthalpy of magnesium sulfide? A. MgS (s) → Mg (g) + S...
• 18M.1.hl.TZ1.16: What is the enthalpy of solution of MgF2(s) in kJ mol−1? Lattice enthalpy of MgF2(s) = 2926 kJ...
• 18M.1.hl.TZ2.16: Which value represents the lattice enthalpy, in kJ mol−1, of strontium chloride, SrCl2? A.   ...

15.2 Entropy and spontaneity

• 15M.1.hl.TZ1.18: Which combination of \(\Delta H\) and \(\Delta S\) values corresponds to a non-spontaneous...
• 15M.1.hl.TZ1.17: Which species are arranged in order of increasing entropy? A.    ...
• 15M.1.hl.TZ2.18: Which combinations of values will result in a spontaneous reaction? A.     I and II only B.  ...
• 15M.2.hl.TZ1.5f.ii: Deduce, giving a reason, the sign of the standard entropy change of the system for the formation...
• 15M.2.hl.TZ2.3b: Calculate the standard free energy change, \(\Delta {G^\Theta }\), in...
• 15M.2.hl.TZ2.3c: Using the values obtained in parts (a) and (b), calculate the standard entropy change,...
• 15M.2.hl.TZ2.3d: Determine the absolute entropy,  \({S^\Theta }\), in...
• 14M.1.hl.TZ1.17: Which reaction has the greatest increase in entropy? A.    ...
• 14M.1.hl.TZ1.18: Which change must be negative when a reaction occurs spontaneously? A.     \(\Delta H\) B.    ...
• 14M.1.hl.TZ2.15: Which combination of enthalpy change and entropy change produces a non-spontaneous reaction at...
• 14M.1.hl.TZ2.17: In which reaction will the entropy of the system increase significantly? A.    ...
• 14M.2.hl.TZ1.4c: Calculate the standard free energy change, \(\Delta {G^\Theta }\), in...
• 14M.2.hl.TZ1.4d: (i)     Determine the standard entropy change of the reaction, \(\Delta {S^\Theta }\), at 298 K,...
• 14N.1.hl.TZ0.16: Which processes have a negative value for \(\Delta {S^\Theta }\)? I.    ...
• 14N.2.hl.TZ0.2d: Predict the sign of the entropy change of the reaction, \(\Delta S\), giving a reason.
• 13N.1.hl.TZ0.18: Which processes are predicted to have a positive entropy change, \(\Delta S\)? I.    ...
• 13N.1.hl.TZ0.19: Which combination of \(\Delta H\) and \(\Delta S\) signs will always result in a spontaneous...
• 13N.2.hl.TZ0.5d: The entropy change, \(\Delta S\), for the decomposition of trinitramide has been estimated as...
• 13N.2.hl.TZ0.5e: Using \( + 700{\text{ J}}\,{{\text{K}}^{ - 1}}{\text{mo}}{{\text{l}}^{ - 1}}\) as the value for...
• 13N.2.hl.TZ0.5f: Explain how changing the temperature will affect whether or not the decomposition of trinitramide...
• 13M.1.hl.TZ1.17: Which process would be expected to have a \(\Delta {S^\Theta }\) value which is negative? A.    ...
• 13M.1.hl.TZ1.18: When solid potassium chlorate, \({\text{KCl}}{{\text{O}}_{\text{3}}}\), dissolves in distilled...
• 13M.2.hl.TZ1.8b.ii: Calculate the standard entropy change for this reaction, \(\Delta {S^\Theta }\), using Table 11...
• 13M.2.hl.TZ1.8b.iii: Calculate, stating units, the standard free energy change for this reaction,...
• 13M.2.hl.TZ1.8b.iv: Predict, with a reason, the effect of an increase in temperature on the spontaneity of this...
• 13M.1.hl.TZ2.17: Which reactions/processes have a positive entropy change, \(\Delta {S^\Theta }\)? I.    ...
• 13M.2.hl.TZ2.5a.i: Predict and explain the sign of the entropy change, \(\Delta S\), for this reaction.
• 13M.2.hl.TZ2.5a.ii: Calculate the standard entropy change for the reaction, \(\Delta {S^\Theta }\), in...
• 13M.2.hl.TZ2.5a.v: Determine the standard free energy change for the reaction, \(\Delta {G^\Theta }\), in...
• 13M.2.hl.TZ2.5a.vi: Deduce the temperature, in K, at which the reaction becomes spontaneous.
• 12N.1.hl.TZ0.18: Consider the following...
• 10N.1.hl.TZ0.18: Which reaction has the largest increase in entropy? A.    ...
• 10N.2.hl.TZ0.7c: (i)     The enthalpy change of formation, \(\Delta H_{\text{f}}^\Theta \), of liquid hydrazine is...
• 09N.1.hl.TZ0.18: Which change leads to an increase in entropy? A.    ...
• 09N.2.hl.TZ0.7b.ii: Predict, stating a reason, whether the sign of \({\Delta {S^\Theta }}\) for the above reaction...
• 09M.1.hl.TZ1.16: Which reaction has the greatest increase in entropy? A.    ...
• 09M.1.hl.TZ1.17: The reaction between but-1-ene and water vapour produces...
• 09M.1.hl.TZ1.18: A reaction has a standard enthalpy change, \(\Delta {H^\Theta }\), of...
• 09M.1.hl.TZ2.18: What is the standard entropy change, \(\Delta {S^\Theta }\), for the following...
• 09M.2.hl.TZ2.4b: The standard entropy for \({\text{C}}{{\text{H}}_{\text{3}}}{\text{OH(g)}}\) at 298 K is...
• 09M.2.hl.TZ2.4c: Calculate the standard change in free energy, at 298 K, for the reaction and deduce whether the...
• 11M.1.hl.TZ1.15: When hydrogen peroxide decomposes, the temperature of the reaction mixture...
• 11M.1.hl.TZ1.16: Which reaction has the greatest increase in entropy? A.    ...
• 11M.2.hl.TZ1.1d: Determine the \(\Delta {S^\Theta }\) for the combustion of...
• 11M.2.hl.TZ1.1e: Using the enthalpy of combustion for methanol from Table 12 of the Data Booklet and the...
• 11M.2.hl.TZ1.1f: Explain whether changing the temperature will alter the spontaneity of the reaction.
• 11M.1.hl.TZ2.19: \(\Delta {G^\Theta }\) calculations predict that a reaction is always spontaneous for which of...
• 11M.2.hl.TZ2.3d: Some words used in chemistry can have a specific meaning which is different to their meaning in...
• 11M.2.hl.TZ2.6b.iii: Calculate the standard entropy change for the hydrogenation of propene.
• 11M.2.hl.TZ2.6b.iv: Determine the value of \(\Delta {G^\Theta }\) for the hydrogenation of propene at 298 K.
• 11M.2.hl.TZ2.6b.v: At 298 K the hydrogenation of propene is a spontaneous process. Determine the temperature above...
• 12M.1.hl.TZ2.17: During which process is there a decrease in the entropy of the system? A.    ...
• 11N.1.hl.TZ0.18: Which factors will increase the entropy of this...
• 11N.1.hl.TZ0.21: The rate expression for the reaction between iodine and propanone with an acid catalyst is found...
• 11N.2.hl.TZ0.5a: Deduce and explain the sign of the entropy change for the following...
• 11N.2.hl.TZ0.5b.iii: Determine the standard free energy change at 298 K for the reaction. Deduce whether or not the...
• 11N.2.hl.TZ0.5b.iv: Determine the standard entropy change at 298 K for the reaction.
• 11N.2.hl.TZ0.5b.v: Estimate the temperature, in K, at which the standard change in free energy equals zero. You...
• 16M.1.hl.TZ0.19: What are the signs for the entropy...
• 16M.2.hl.TZ0.2a: (i) Deduce the equilibrium constant expression, Kc, for this reaction. (ii) At exactly 600°C the...
• 16N.2.hl.TZ0.1b: (i) Calculate ΔHθ, in kJ, for this similar reaction below using \(\Delta H_{\rm{f}}^\theta \)...
• 17M.1.hl.TZ1.17: Which combination of ΔH θ and ΔS θ will result in a non-spontaneous reaction at all temperatures?
• 17M.2.hl.TZ1.3c.ii: Comment on the spontaneity of this reaction by calculating a value for \(\Delta {G^\theta...
• 17M.2.hl.TZ1.4c.i: Calculate the standard entropy change, \(\Delta {S^\theta }\), of the reaction, in...
• 17M.2.hl.TZ1.4c.ii: Calculate a value for \(\Delta {H^\theta }\) in kJ.
• 17M.2.hl.TZ1.4c.iii: Use your answers to (c)(i) and (c)(ii), to determine the temperature, in °C, at which the...
• 17M.2.hl.TZ2.9b.i: Hydrogenation of propene produces propane. Calculate the standard entropy change, ΔS θ, for the...
• 17M.2.hl.TZ2.9b.ii: The standard enthalpy change, ΔH θ, for the hydrogenation of propene is –124.4 kJ mol–1. Predict...
• 17N.1.hl.TZ0.16: What is the standard enthalpy of formation, in kJ mol–1, of IF (g)? IF7 (g) + I2 (s) → IF5 (g) +...
• 17N.1.hl.TZ0.17: The combustion of glucose is exothermic and occurs according to the following equation: C6H12O6...
• 17N.2.hl.TZ0.5b: Calculate the standard entropy change for this reaction using the following data.
• 17N.2.hl.TZ0.5c: The standard free energy change, ΔGθ, for the above reaction is –103 kJ mol–1 at 298 K. Suggest...
• 18M.1.hl.TZ1.17: Which statement is correct? A.     If ΔH < 0, reaction is always spontaneous. B.     If ΔH...
• 18M.2.hl.TZ1.3c.iv: Calculate the standard entropy change, ΔSΘ, in J K−1, for the reaction in (ii) using section 12...
• 18M.2.hl.TZ1.3c.v: Determine, showing your working, the spontaneity of the reaction in (ii) at 25 °C.
• 18M.1.hl.TZ2.17: Which system has the most negative entropy change, ΔS, for the forward reaction? A.     N2(g) +...
• 18M.2.hl.TZ2.5c: The table lists standard entropy, SΘ, values. Calculate the standard entropy change for the...
• 18M.2.hl.TZ2.5d: Calculate the standard free energy change, ΔGΘ, in kJ, for the reaction at 298 K using your...
• 18M.2.hl.TZ2.5e: Determine the temperature, in K, above which the reaction becomes spontaneous.