Table of contents

1. Intro to General Chemistry3h 48m
2. Atoms & Elements4h 16m
3. Chemical Reactions4h 10m
4. BONUS: Lab Techniques and Procedures1h 38m
5. BONUS: Mathematical Operations and Functions48m
6. Chemical Quantities & Aqueous Reactions3h 53m
7. Gases3h 49m
8. Thermochemistry2h 37m
9. Quantum Mechanics2h 58m
10. Periodic Properties of the Elements3h 9m
11. Bonding & Molecular Structure3h 29m
12. Molecular Shapes & Valence Bond Theory1h 57m
13. Liquids, Solids & Intermolecular Forces2h 23m
14. Solutions3h 1m
15. Chemical Kinetics2h 53m
16. Chemical Equilibrium2h 29m
17. Acid and Base Equilibrium5h 1m
18. Aqueous Equilibrium4h 47m
19. Chemical Thermodynamics1h 50m
20. Electrochemistry2h 42m
21. Nuclear Chemistry2h 36m
22. Organic Chemistry5h 7m
23. Chemistry of the Nonmetals2h 39m
24. Transition Metals and Coordination Compounds3h 16m

8. Thermochemistry

Internal Energy

General Chemistry

8. Thermochemistry

Internal Energy

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Multiple Choice

An unknown gas expands in a container increasing the volume from 4.3 L to 8.2 L at a constant pressure of 931 mmHg. Calculate the internal energy of the system if the system absorbs 2.3 kJ of energy.

2.3 kJ

1.8 kJ

1.2 kJ

2.8 kJ

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Verified step by step guidance

Identify the given values: initial volume (V1) = 4.3 L, final volume (V2) = 8.2 L, constant pressure (P) = 931 mmHg, and energy absorbed (q) = 2.3 kJ.

Convert the pressure from mmHg to atm for consistency in units, using the conversion factor: 1 atm = 760 mmHg.

Calculate the work done by the system using the formula: \( w = -P \Delta V \), where \( \Delta V = V2 - V1 \). Ensure the pressure is in atm and the volume change is in liters.

Use the first law of thermodynamics, which states \( \Delta U = q + w \), where \( \Delta U \) is the change in internal energy, \( q \) is the heat absorbed, and \( w \) is the work done by the system.

Substitute the values of \( q \) and \( w \) into the equation to find \( \Delta U \). Remember to convert the work from L·atm to kJ using the conversion factor: 1 L·atm = 0.1013 kJ.