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

12. Molecular Shapes & Valence Bond Theory

Molecular Geometry

General Chemistry

12. Molecular Shapes & Valence Bond Theory

Molecular Geometry

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Multiple Choice

Determine the molecular geometry for the following molecule:SeH₂Cl₂

T-shaped

Seesaw

Square pyramidal

Square planar

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Verified step by step guidance

Identify the central atom in the molecule. In SeH2Cl2, the central atom is selenium (Se).

Determine the total number of valence electrons for the molecule. Selenium has 6 valence electrons, each hydrogen has 1, and each chlorine has 7. Calculate the total: 6 (Se) + 2*1 (H) + 2*7 (Cl).

Use the VSEPR (Valence Shell Electron Pair Repulsion) theory to predict the molecular geometry. Count the number of bonding pairs and lone pairs around the central atom. SeH2Cl2 has 4 bonding pairs and 1 lone pair.

Based on the VSEPR theory, a molecule with 4 bonding pairs and 1 lone pair around the central atom adopts a 'seesaw' shape. This is because the lone pair occupies one of the equatorial positions in a trigonal bipyramidal arrangement, causing the remaining atoms to form a seesaw shape.

Verify the molecular geometry by considering the positions of the atoms and lone pairs. The lone pair on selenium will repel the bonding pairs, leading to the seesaw geometry, which is consistent with the VSEPR model for this electron arrangement.