Hello,
This post is about balancing chemical equations. This is done to satisfy the Law of Conservation of Matter. This law states that any amount of matter going into a chemical process (i.e. The Reactants) must equal the amount of matter coming out of the chemical process (i.e. The Products). We balance a chemical equation by placing appropriate whole numbers to the left of chemical formulas in the equation. This has a multiplying effect on the number of atoms of an element contained in a formula. In the case where there is a subscript to the right of an element symbol, the number added to the left of a formula (the coefficient) is multiplied by the subscript to obtain the contribution of element atoms contributed for that formula. If a formula contains a polyatomic ion (a covalently bonded cluster of two or more atoms, usually of different elements, with a charge) the number of atoms contribution for an element (in the polyatomic ion) is obtained by multiplying the outer subscript by the element's inner subscript by the formula coefficient. Whew! I'll have an example of this within a drawing included with this post.
After studying chemistry for some time, a person has experience balancing chemical equations and eventually discovers "little" best-practices or rules to use. Normally, you do not see these rules presented in a textbook. I think it is better to learn these rules "up-front" and to use them when practicing equation-balancing. If the rules are not used, balancing certain chemical equations seems considerably more challenging. Plus, using the rules helps the chemistry student gain some understanding about how the chemical reaction actually occurs! The graphic below lists these rules. I like to call them, Pastore's Thumb Rules for Balancing Chemical Equations.
This first example uses thumb-rule c. This is an acid base reaction which always results in the formation of water. Whenever water is decomposed or produced use rule c.
The following second example is balancing the chemical equation for the combustion of ethanol. Rules a, b, and e are used for this one.
Always remember to include the contribution of Oxygen for the combustion of alcohols, ketones, aldehydes, esters, and ethers. An upcoming post will feature balancing chemical equations for polyatomic ion - containing compounds.
Have a Good One!
A publication of http://www.excellenceinlearning.biz
This post is about balancing chemical equations. This is done to satisfy the Law of Conservation of Matter. This law states that any amount of matter going into a chemical process (i.e. The Reactants) must equal the amount of matter coming out of the chemical process (i.e. The Products). We balance a chemical equation by placing appropriate whole numbers to the left of chemical formulas in the equation. This has a multiplying effect on the number of atoms of an element contained in a formula. In the case where there is a subscript to the right of an element symbol, the number added to the left of a formula (the coefficient) is multiplied by the subscript to obtain the contribution of element atoms contributed for that formula. If a formula contains a polyatomic ion (a covalently bonded cluster of two or more atoms, usually of different elements, with a charge) the number of atoms contribution for an element (in the polyatomic ion) is obtained by multiplying the outer subscript by the element's inner subscript by the formula coefficient. Whew! I'll have an example of this within a drawing included with this post.
After studying chemistry for some time, a person has experience balancing chemical equations and eventually discovers "little" best-practices or rules to use. Normally, you do not see these rules presented in a textbook. I think it is better to learn these rules "up-front" and to use them when practicing equation-balancing. If the rules are not used, balancing certain chemical equations seems considerably more challenging. Plus, using the rules helps the chemistry student gain some understanding about how the chemical reaction actually occurs! The graphic below lists these rules. I like to call them, Pastore's Thumb Rules for Balancing Chemical Equations.
This first example uses thumb-rule c. This is an acid base reaction which always results in the formation of water. Whenever water is decomposed or produced use rule c.
The following second example is balancing the chemical equation for the combustion of ethanol. Rules a, b, and e are used for this one.
Always remember to include the contribution of Oxygen for the combustion of alcohols, ketones, aldehydes, esters, and ethers. An upcoming post will feature balancing chemical equations for polyatomic ion - containing compounds.
Have a Good One!
A publication of http://www.excellenceinlearning.biz
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