PreparED Study Materials
Notes
Study Guides
Videos
Number of molecules in 3.5g H?O, 56.1g N?, 89g CCl?, 19g C?H??O?
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This video shows how to determine the number of molecules in a given sample by utilizing the concept of moles, Avogadro's number (6.022 x 10²³), and the molar mass of the substance. It provides step-by-step calculations for different substances, converting mass to the number of molecules and highlighting the versatile application of this approach.
BrF?, ClF?, & IF? Lewis Structures: Which Don't Obey Octet Rule?
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Unravel the Lewis structures of BrF?, ClF?, and IF? and their relationship with the octet rule. Examine how fluorine bonds with bromine, chlorine, and iodine. Identify molecules that deviate from the standard octet distribution.
Unveiling Earth's Crust: Calculating Silicon Mass
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Explore the fascinating process of calculating the mass of silicon in Earth's crust. Learn how to convert Earth's total mass to grams, determine the crust's mass percentage, and find the silicon's mass within the crust. Discover the scale of silicon's presence in our planet's outer layer.
Identifying Fundamental Units in Rb?O, N?, Fe(NO?)?, and N?F?
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In this exploration, we delve into the fundamental units of various substances, whether they are single atoms, molecules, or formula units. We examine ionic compounds like Rb?O and Fe(NO?)?, characterized by formula units as their basic components, and covalent compounds like N? and N?F?, where molecules are the fundamental units.
Ethylene Glycol & Freezing Point in Antifreeze
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We explore the impact of increasing the concentration of ethylene glycol in an antifreeze mixture, explaining the resulting effect on the freezing point of the solution by examining its interaction with water molecules.
Nickel(II) Nitrate Solution Composition Analysis
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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.











