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WorksheetsThermochemistry
Total questions: 10
Worksheet time: 19mins
Which of the following halides has the highest value (most exothermic) for its lattice energy?
KI
NaBr
NaF
KF
The enthalpy changes, H for two reactions are given by the equations below.
2Fe(s) + 1 ½ O2 (g) à Fe2O3 (s) H = – 822 kJ mol – 1
C (s) + ½ O2 (g) à CO (g) H = – 110 kJ mol – 1
What is the enthalpy change for the reaction,
3C (s) + Fe2O3 (s) à 2Fe (s) + 3CO (g)?
+ 712 kJ mol – 1
+492 kJ mol – 1
– 492 kJ mol – 1
– 712 kJ mol – 1
The second ionisation energy for calcium is 1150 kJ mol– 1 . Which of the following represents this statement accurately?
Ca (g) -->Ca2+(g) + 2e H = +1150 kJ mol– 1
Ca(s) --> Ca2+(g) + 2e H = +1150 kJ mol– 1
Ca+(s) --> Ca2+(s) + e H = +1150 kJ mol– 1
Ca+(g) --> Ca2+(g) + e H = +1150 kJ mol– 1
Which of the following equations represent the formation of a compound?
H2 (g) + O2(g) --> H2O2 (g)
Zn (s) + S (s) --> ZnS (s)
K (s) + Cl (g) --> KCl (s)
CH2=CH2(g) + Br2(g) --> CH2BrCH2Br (l)
The standard enthalpy of formation of CO2 and H2O are -394 kJ mol-1 and -286 kJ mol-1 respectively. If the standard enthalpy of combustion of ethene is -1411 kJ mol-1, what is the standard enthalpy of formation of ethene?
- 235 kJ mol-1
- 445 kJ mol-1
+ 51 kJ mol-1
+ 83 kJ mol-1
The energy diagram for the combustion of ethanoic acid, C2H4O2 is shown.
The enthalpy of combustion for ethanoic acid is – 1360 kJ mol-1
The enthalpy of formation of water is – 286 kJ mol-1
The enthalpy of combustion for carbon is – 394 kJ mol
The solubility of an ionic compound depends on
lattice energy
ionsation energy
hydration energy
The N2O4 molecule is the dimer for the NO2 molecule. The enthalpy for the formation of N2O4 and NO2 are + 9.67 kJ mol-1 and + 33.86 kJ mol-1 respectively. Calculate the standard enthalpy change for the formation (in kJ mol-1) of N2O4 from NO2.
– 58.05 kJ mol-1
+ 58.05 kJ mol-1
+ 24.19 kJ mol-1
– 24.19 kJ mol-1
Phosphorus(V) chloride decomposes to phosphorus(III) chloride and chlorine when heated.
PCl5 (g) --> PCl3 (g) + Cl2 (g)
Calculate the enthalpy change (in kJ mol-1) for the above reaction.
[Bond energy = P – Cl = +330 kJ mol-1; Cl – Cl = + 240 kJ mol-1 ]
- 420
+ 420
- 90
+ 90
Which of the following processes are endothermic?
Cl2 (g) --> 2Cl (g)
Na (s) --> Na (g)
Na+ (g) + Cl- (g) --> NaCl (s)
