PreparED Study Materials
CHEM 267: CHEM 267
School: University of Massachusetts
Number of Notes and Study Guides Available: 3
Notes
Videos
Iron Bar: Mass Change and Rust Formation
Want To Learn More? To watch the entire video and ALL of the videos in the series:
full solution
Learn about mass changes in an iron bar when exposed to moist air, including the formation of rust (Fe?O?) and how to calculate the final mass.
Comparing O-O Bond Lengths: Hydrogen Peroxide vs. Oxygen Molecule
Want To Learn More? To watch the entire video and ALL of the videos in the series:
full solution
Explore the intricacies of hydrogen peroxide's Lewis structure and its bond characteristics. Understand the differences in bond lengths between H?O? and O?. Delve into the distinction between single and double bonds and their implications.
Analyzing Molecular Structure Levels in DNA, tRNA, and mRNA
Want To Learn More? To watch the entire video and ALL of the videos in the series:
full solution
This video explores the concept of structural levels (primary, secondary, tertiary, and quaternary) in biomolecules, focusing on double-stranded DNA, tRNA, and mRNA to understand the diverse ways these molecules exhibit these structural layers.
Lattice Energy: Always Positive; Hydration Energy: Always Negative
Want To Learn More? To watch the entire video and ALL of the videos in the series:
full solution
In this video we clarify why lattice energy in solids is always a positive value due to the energy needed to separate ions making it an endothermic process. On the flip side hydration energy is always negative as it releases heat when ions dissolve in water making it an exothermic reaction. We use sodium chloride as a real-world example to illustrate these crucial thermodynamic concepts
Determining Neutrons from Atomic & Mass Numbers: A Comprehensive Guide
Want To Learn More? To watch the entire video and ALL of the videos in the series:
full solution
Understand the relationship between atomic number, mass number, and neutrons within atoms. This video breaks down the simple calculation to determine the number of neutrons for specific elements like Nickel, Uranium, Scandium, and Argon.
Making a 0.150 M Ba(OH)? Solution: A Step-by-Step Guide
Want To Learn More? To watch the entire video and ALL of the videos in the series:
full solution
Learn how to calculate the amount of Barium hydroxide, Ba(OH)?, needed to prepare a specific molar concentration. This tutorial breaks down the relationship between moles of hydroxide ions and moles of Ba(OH)?, guiding users through each step for precise results. Embrace the essence of molarity in solution preparation.














