Enthalpy Stoichiometry Worksheet
Grade 12 Chemistry worksheet focusing on enthalpy changes in stoichiometric calculations, including Hess's Law and standard enthalpies of formation.
Includes
Standards
Enthalpy Stoichiometry
Name:
Date:
Score:
Read each question carefully and answer to the best of your ability. Show all your work for calculations.
1. Define enthalpy and explain its significance in chemical reactions.
2. An exothermic reaction releases heat to the surroundings, resulting in a ΔH value.
3. Hess's Law states that if a reaction can be expressed as the sum of two or more steps, the enthalpy change for the overall reaction is the of the enthalpy changes for the individual steps.
4. Which of the following statements is true regarding standard enthalpy of formation (ΔH°f)?
It is the enthalpy change when one mole of a compound is formed from its elements in their standard states at 1 atm and 25°C.
It is always a positive value.
It refers to the enthalpy change for any reaction that produces one mole of a compound.
It is only applicable to reactions at 0°C.
5. Given the following reactions:
C(s) + O₂(g) → CO₂(g) ΔH = -393.5 kJ/mol
H₂(g) + ½O₂(g) → H₂O(l) ΔH = -285.8 kJ/mol
C₂H₂(g) + ⁵⁄₂O₂(g) → 2CO₂(g) + H₂O(l) ΔH = -1300 kJ/mol
Calculate the standard enthalpy of formation (ΔH°f) for C₂H₂(g) using Hess's Law.
6. In an endothermic reaction, the products have lower enthalpy than the reactants.
True
False
7. Calculate the heat released when 50.0 g of methane (CH₄) is completely combusted, given that the standard enthalpy of combustion for methane is -890.3 kJ/mol.
Related Worksheets
Grade 12 Burette Reading Worksheet
A worksheet for Grade 12 Chemistry students to practice reading and understanding burette measurements.
Balancing Nuclear Reactions Worksheet
Grade 12 Science worksheet focused on balancing nuclear equations, identifying types of decay, and understanding nuclear stability.
Hydrocarbons Worksheet
Grade 12 Chemistry worksheet covering the nomenclature, structure, properties, and reactions of various hydrocarbon classes.
Grade 12 Molecular Structure Worksheet
A Grade 12 Chemistry worksheet focusing on molecular structure, VSEPR theory, hybridization, and intermolecular forces.
Percent Abundance of Isotopes Worksheet
Grade 12 Chemistry worksheet on understanding and calculating percent abundance of isotopes, average atomic mass, and mass spectrometry.
Acid-Base Nomenclature Worksheet
A Grade 12 Chemistry worksheet covering the nomenclature of acids and bases, including common naming conventions and formulas.
Ionic Bonds Worksheet
A Grade 12 Chemistry worksheet exploring the principles of ionic bonding, including formation, properties, and examples.
Ionic Bonds Worksheet
A Grade 12 Chemistry worksheet exploring the principles of ionic bonding, including formation, properties, and examples.