CHEM 111: Chemistry 111

Understand the fundamental distinctions between pure substances and mixtures. Unpack the definitions and real-world examples of elements, compounds, homogeneous, and heterogeneous mixtures.

Discover the differences between physical and chemical changes using common examples. Understand how sugar reacts in various scenarios, and how metals undergo changes, either maintaining their substance or forming new compounds.

In this video, we delve into the concept of percent composition by mass, exemplified through the compound chloroform (CHCl?), which was once employed as an inhalation anesthetic despite its associated toxicity. By calculating the percent composition for each element within the compound, we gain valuable insights into its composition and its potential effects on health and properties.

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).

Discover the contrasting processes of vaporization and condensation and their thermal nature. Understand why boiling is endothermic, absorbing heat, while condensation is exothermic, releasing heat, and how these processes impact ?H values.