20Apr 2019 by Vincent Summers No Comments

The Conversion of Cane Juice to Sugar: a Chemical or Physical Change?

Chemistry, Food
[caption id="attachment_24130" align="alignright" width="480"] Harvested sugarcane.[/caption] One of our readers asks, “So, is the crystallization process of cane juice to raw sugar considered a chemical change or a physical change? Why one or the other?” Let’s discuss, starting with an explanation of what constitutes a chemical change. What is a Chemical Change? A chemical compound consists of atoms bonded together in specific fashion to form molecules. When you modify the combination of atoms, you’ve achieved a chemical change. For instance, combine sodium hydroxide with hydrochloric acid, and the result is sodium chloride (table salt) and water, according to the reaction: NaOH + HCl → NaCl + H₂O This example clearly represents a chemical change. Salt (NaCl) is edible, sodium hydroxide or lye (NaOH) is not. Water (H₂O) is safe for…
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18Apr 2019 by Vincent Summers 1 Comment

Introduction to Chemistry Subscripts and Superscripts

Chemistry, Education
Subscript and superscript can make all the difference when it comes to chemical formulas. Molecules, compounds, and other chemical structures include more than one atom. Sometimes, there are multiples of one particular atom. For instance, anhydrous aluminum chloride features one atom of aluminum joined to or combined with three atoms of chlorine. Its chemical formula reflects this: AlCl3. But – simply knowing how to use a number in this instance is not enough. It is essential to know the proper use of subscripts and superscripts. Subscripts in Chemistry Notice the number 3 is written as a subscript, or a number that is smaller than the other text, and below the normal text line, in the formula for anhydrous aluminum chloride above. The concept of a multiplicity of atoms is conveyed…
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27Oct 2014 by Vincent Summers No Comments

Anhydrides – Inorganic and Organic

Chemistry
Anhydrides are compounds that are similar to other compounds from which one or more molecules of water has been eliminated. An anhydride must not be confused with an anhydrous compound. In an anhydrous compound, the water reactant from which it is formed includes water that is attached lightly by weak bonds. Water is not an inherent part of the molecule's structure. Consider cupric sulfate pentahydrate, CuSO₄•5H₂O. This is a blue, crystalline substance. It is a composite structure of one molecule of cupric sulfate and five weakly held molecules of water of crystallization. Those water molecules can be removed quite easily. Powdering the crystals and warming them in a drying oven produces CuSO₄. This anhydrous compound is nearly white. No, it is not an anhydride. Aluminum Oxide Aluminum oxide, Al₂O₃, is an…
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