CHEM 1172: General Chemistry II

This video tackles the classification of boiling water as either a physical or chemical change, examining the provided options. We conclude that boiling is a physical change, as the water's chemical composition remains the same during the transition from liquid to gas.

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.

Learn the art of precise chemical calculations in this video. Discover how Chromium(III) oxide reacts with hydrogen sulfide to form chromium(III) sulfide and water, all while unraveling the necessary steps to determine the exact quantities involved.

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).

We explore Lewis structures, which depict atom bonding and lone electron pairs. We create Lewis structures for potassium, barium, aluminum, and bromine by using group numbers in the periodic table to determine their valence electrons.

Discover how to precisely calculate mass, moles, formula units, and atoms in various compounds. Understand the concept with examples like chromium(III) sulfate decahydrate, dichlorine heptoxide, and lithium sulfate. Master chemistry calculations through a step-by-step guide.