Standard Enthalpy of Formation
Chemistry ⇒ Thermochemistry and Energetics
Standard Enthalpy of Formation starts at 11 and continues till grade 12.
QuestionsToday has an evolving set of questions to continuously challenge students so that their knowledge grows in Standard Enthalpy of Formation.
How you perform is determined by your score and the time you take.
When you play a quiz, your answers are evaluated in concept instead of actual words and definitions used.
See sample questions for grade 12
Describe how Hess's Law is used to determine the standard enthalpy of formation of a compound.
Describe the difference between standard enthalpy of formation and standard enthalpy of combustion.
Describe the significance of the sign (positive or negative) of the standard enthalpy of formation value.
Explain why the standard enthalpy of formation of a compound is important in thermochemistry.
Calculate the standard enthalpy change for the reaction: 2CO(g) + O2(g) → 2CO2(g), given ΔHf°[CO2(g)] = -393.5 kJ mol-1 and ΔHf°[CO(g)] = -110.5 kJ mol-1.
Calculate the standard enthalpy change for the reaction: 2H2O(l) → 2H2(g) + O2(g), given ΔHf°[H2O(l)] = -285.8 kJ mol-1.
Fill in the blank: The standard enthalpy of formation of NaCl(s) is ______ kJ mol-1 if the reaction is Na(s) + 1/2 Cl2(g) → NaCl(s), ΔH = -411 kJ mol-1.
Fill in the blank: The standard enthalpy of formation of SO2(g) is ______ kJ mol-1 if the reaction is S(s) + O2(g) → SO2(g), ΔH = -296.8 kJ mol-1.
Which of the following best defines the standard enthalpy of formation (ΔHf°)? (1) The enthalpy change when 1 mole of a compound is formed from its elements in their standard states under standard conditions. (2) The enthalpy change when 1 mole of a compound is decomposed into its elements in their standard states. (3) The enthalpy change when 1 mole of a compound is formed from its ions in solution. (4) The enthalpy change when 1 mole of a compound is burned in oxygen.
Which of the following compounds has a standard enthalpy of formation of zero? (1) O2(g) (2) H2O(l) (3) CO2(g) (4) NaCl(s)
Which of the following is NOT a standard state for the element at 298 K and 1 bar? (1) H2(g) (2) O2(g) (3) C(diamond) (4) C(graphite)
Which of the following is the correct standard enthalpy of formation equation for Al2O3(s)? (1) 2Al(s) + 3/2 O2(g) → Al2O3(s) (2) Al(s) + O2(g) → Al2O3(s) (3) 2Al(s) + 3O2(g) → 2Al2O3(s) (4) Al2O3(s) → 2Al(s) + 3/2 O2(g)
Fill in the blank: The standard enthalpy of formation is measured under standard conditions, which are ______ K temperature and 1 bar pressure.
Fill in the blank: The standard enthalpy of formation of NaCl(s) is ______ kJ mol-1 if the reaction is Na(s) + 1/2 Cl2(g) → NaCl(s), ΔH = -411 kJ mol-1.
Fill in the blank: The standard enthalpy of formation of SO2(g) is ______ kJ mol-1 if the reaction is S(s) + O2(g) → SO2(g), ΔH = -296.8 kJ mol-1.
Fill in the blank: The standard enthalpy of formation of an ionic compound in aqueous solution is based on the formation of the compound from its elements in their standard states, with all ions at a concentration of ______ mol dm-3.
True or False: The standard enthalpy of formation can be positive, negative, or zero.
True or False: The standard enthalpy of formation is always measured for 1 mole of product.
True or False: The standard enthalpy of formation of a compound can be determined experimentally.
True or False: The standard enthalpy of formation of a compound is always less than zero.
