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Showing posts with the label chemical

Oxidation of Magnesium - Empirical Formula

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This video summarizes an experiment performed to experimentally determine the empirical formula of magnesium oxide. In the lab the mass of a small sample of magnesium ribbon is measured. The metal is then heated in a crucible using a Bunsen burner to speed up the process of oxidation. The reaction forms the product magnesium oxide. The mass of this compound is measured and compared to the original amount of magnesium to determine the added mass of oxygen. The data collected allows students to calculate the empirical formula of the magnesium oxide compound. The reaction is summarized by the following chemical equation. 2Mg  +  O 2  →  2MgO The compound forms with a 1:1 ratio of magnesium to oxygen. This is because magnesium has two valence electrons which are donated to the oxygen atoms. The oxygen atoms can add two electrons to complete their valence shell. I hope this was helpful.

HS-PS1-2: Chemical Reactions

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HS-PS1-2:   Construct and revise an explanation for the outcome of a simple chemical reaction based on the outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical properties. HS-PS1-2 Evidence Statements Video example of a chemical reaction. The video shows the combustion of magnesium metal.   2Mg  +  O 2  →  2MgO When magnesium and oxygen react they form an ionic compound. This is due to the fact that magnesium is a metallic element and oxygen is nonmetallic.

Thermal Decomposition of Baking Soda

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A thermal decomposition reaction occurs when heat is applied to a compound causing it to decompose (break down) into multiple different chemical substances. An example is when baking soda (sodium bicarbonate) is heated 2 N a H C O 3 ( s ) → C O 2 ( g ) + H 2 O ( g ) + N a 2 C O 3 ( s ) Here is a video discussion of this reaction... I hope this was helpful!

Stock Naming System in Chemistry

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The stock naming system uses roman numerals to indicate the oxidation state of metal ions in ionic compounds.  It is used because many metals have more than one possible oxidation state (charge).  One example of this is tin.  The two most common oxidation states of tin are 2+ and 4+; a Roman numeral is used in the name of the compound to tell us which oxidation state is present in a given compound of tin. In the past it was also common to see names of compounds using their Latin names.  Some examples include ferrum for iron and aurum for gold.  In the Latin naming system, different suffixes are used to indicate the oxidation state of the metal ion. I hope this is helpful!

Calculating the pH of a Strong Acid or Strong Base

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This video provides examples of how you can calculate the pH of a strong acid or strong base if you are given just the concentration (molarity) of the solution. I hope this is helpful!

HS-PS1-2: Trends of the Periodic Table

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HS-PS1-2:   Construct and revise an explanation for the outcome of a simple chemical reaction based on the outermost electron states of atoms, trends in the periodic table, and knowledge of the patterns of chemical properties. This video covers important trends of the periodic table.  Topics include; reactivity, ionization energy, successive ionization energy, atomic radius, ionic radius, electron affinity, and electronegativity.

HS-PS1-7: Mass is conserved in chemical reactions

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HS-PS1-7:   Use mathematical representations to support the claim that atoms, and therefore mass,  are conserved during a chemical reaction. PS1-7 Evidence Statements The video below discusses the decomposition reaction of hydrogen peroxide and uses a balanced chemical equation and structural formulas to explain why the number of atoms is conserved in a chemical reaction. An experiment to help teach the concept of conservation of mass can be found here .