Ch.6 - Thermochemistry WorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Solution: In a calorimetry experiment a student determines the enthalpy for the reaction of magnesium with hydrochloric acid to be -430 kJ/mol. The true enthalpy for this reaction is -450 kJ/mol. Which of the f

Problem

In a calorimetry experiment a student determines the enthalpy for the reaction of magnesium with hydrochloric acid to be -430 kJ/mol. The true enthalpy for this reaction is -450 kJ/mol. Which of the following sources of error could account for this discrepancy?

a. After recording the mass, some of the magnesium was dropped on the counter

b. Some of the hot hydrogen gas escaped during the reaction.

c. The calorimeter was not tightly shut for the experiment.

d. The final temperature was recorded before the reaction was complete.

e. All of these errors would cause a falsely high value for the enthalpy