CHEM 121: Principles of Chemistry I

In this video we explore the process of calculating the weight percent of barium potassium and chlorine in a mixed sample of barium chloride dihydrate and potassium chloride. Through a step-by-step approach we examine the changes in sample weight after heating to 160°C breaking down the calculations for each elemental content.

Join us in this video as we dive into the intricacies of calculating the net ATP yield from oleic acid (18:1 ??). We'll provide a step-by-step guide and offer helpful hints to ensure an accurate calculation, including a critical step that bypasses acyl-CoA dehydrogenase.

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

This video discusses the fundamental concept of DNA structure, focusing on the identification of the 3' and 5' ends of a DNA segment, specifically highlighting the sequence AGTCAT and its importance in understanding DNA strand direction for processes like replication and transcription.

This video outlines the process of calculating the number of moles in various elemental samples. It begins by explaining the relationship between molar mass and atomic weight. Each sample's mass is divided by the respective element's molar mass to find the number of moles. It provides detailed calculations for four elemental samples: zinc (Zn), argon (Ar), tantalum (Ta), and lithium (Li), converting results to scientific notation where necessary. The script demonstrates how to determine the mole

In this video, the problem involves calculating the mass of magnesium oxide (MgO) produced when 14.8 liters of oxygen gas react with magnesium metal according to the chemical equation 2Mg + O2 -> 2MgO. The stoichiometric relationship is used to determine that 0.6607 moles of oxygen gas results in 1.3214 moles of MgO, with a final calculation yielding a mass of 53.25 grams of MgO formed during the reaction at Standard Temperature and Pressure (STP).