CHEM 107: Chemistry

This instructional video guides you through the process of determining the number of molecules in a given sample. It illustrates the conversion from grams to moles using the molar mass of the substance and then to molecules using Avogadro's number, providing a practical example with ethane (C?H?) to calculate approximately 6.67 x 10²¹ molecules in a 0.334 g sample.

In this video, we delve into the fascinating world of evolutionary adaptations in heme-containing proteins.

This instructional video demonstrates the process of calculating the mass percent of various solutions, using the formula "mass of solute divided by mass of solution, all multiplied by 100%." It provides step-by-step calculations for three different solutions, revealing the concentration of each solute in terms of mass percent, offering a practical understanding of quantifying solute proportions in solutions.

Explore the protonation of amino acids, specifically valine and threonine, when subjected to a pH lower than their isoelectric points, highlighting the structural changes in their carboxyl and amino groups.

In this analysis, we determine the composition of a solution prepared by dissolving 12.15g of nickel(II) nitrate in 175mL of water (density 1.00 g/mL). The mass percent of nickel(II) nitrate is found to be approximately 6.50%, and the mole fraction of nickel(II) ions in the solution is calculated as 0.00672.

Explore the classification of select molecules based on their polarity. Understand the electron distribution and molecular shapes of Formaldehyde, Methanol, Dichloromethane, and Carbon dioxide. Discover which ones exhibit a net dipole moment and which ones don't.