balancing Chemical Equations
Level 14 Guiding Question: Why do we need to balance chemical Equations?
The 5 steps in balancing equations
Example of Balancing a Chemical Equation:
? C3H8O2 + ? O2 → ? H2O + ?CO2
? C3H8O2 + ? O2 → ? H2O + ?CO2
Step 1Identify each element in the equation. The number of atoms of each type of atom must be the same on each side of the equation once it has been balanced.
H is found in CH4 and H2O, so it's a good starting element. Step 4
Once you have balanced one element, do the same thing with another element. Proceed until all elements have been balanced. It's easiest to leave elements found in pure form for last.
Finally, determine the O coefficient. You can see you need to double the O2 coefficient in order to get 4 O seen on the product side of the reaction.1 CH4 + 2 O2 → 1 CO2 + 2 H2O |
Step 2What is the net charge on each side of the equation? The net charge must be the same on each side of the equation once it has been balanced.
You have 4 H in CH4 yet only 2 H in H2O, so you need to double the coefficient of H2O to balance H.1 CH4 + ? O2 → ? CO2 + 2 H2O 1. ___ SnO₂ + ___ H₂ → ___ Sn + ___ H₂O
2. __ KOH + __ H₃PO₄ → __ K₃PO₄ + __ H₂O |
Step 3Start with an element found in one compound on each side of the equation. Change the coefficients (the numbers in front of the compound or molecule) so that the number of atoms of the element is the same on each side of the equation.
Looking at carbon, you can see that CH4 and CO2 must have the same coefficient.1 CH4 + ? O2 → 1 CO2 + 2 H2O Step 5
Check your work to make certain the charge on both sides of the equation is also balanced.
Check your work. It's standard to drop a coefficient of 1, so the final balanced equation would be written:CH4 + 2 O2→ CO2 + 2 H2O. |
Watch the Balancing Chemical Equations Google Slide Presentation
A chemical equation is a written description of what happens in a chemical reaction. The starting materials, called reactants are listed on the lefthand side of the equation. Next comes an arrow that indicates the direction of the reaction. The righthand side of the reaction lists the substances that are made, called products.
A balanced chemical equations tells you the amounts of reactants and products needed to satisfy the Law of Conservation of Mass. Basically, this means there are the same numbers of each type of atoms on the left side of the equation as there are on the right side of the equation. It sounds like it should be simple to balance equations, but it's a skill that takes practice. So, while you might feel like a dummy, you're not! Here's the process you follow, step by step, to balance equations. You can apply these same steps to balance any unbalanced chemical equation... |
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Level 14 Investigation: How to balance chemical equations
Read the online chapter above or watch the videos in the "VDO" section and don't forget to do the practice problems and the PLIX activity. After you have practiced the concepts of balancing chemical equations download and print the practice problems after you have completed them please turn them in to your instructor of post them to your Google Classroom account.
Level 14 Investigation: balancing nuts and bolts
Chemical reactions occur when a certain number of reactants react with a certain number of another reactant (given as coefficients in the balanced equation). We can see this information to determine the mass of reactants needed, and the mass of products formed if we know the average masses of the species involved. This is called stoichiometry. In this activity, you will consider the ideas of stoichiometry with nuts and bolts.
You have a cup with some nuts and bolts. The product that you are to make consists of two nuts on each bolt. Your goal is to make as many of the product as possible. Click the images below to enlarge them. When you have completed the lab fill out page 2 (analysis page) and turn it in via the instructor or Google classroom.
You have a cup with some nuts and bolts. The product that you are to make consists of two nuts on each bolt. Your goal is to make as many of the product as possible. Click the images below to enlarge them. When you have completed the lab fill out page 2 (analysis page) and turn it in via the instructor or Google classroom.
Level 14 Video: Techniques on how to Balance Chemical equations
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Level 14 Elaborate: Can you show someone else how to balance Equations?
Click on the button to your right and use the worksheet provided to complete the assignment with the on-line Balancing Equation.
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If you need a hard copy click on the button above. When you have completed your assignment turn it in to your instructor or post it on your Google Classroom page.
Level 14 Review: What do you need......Practice ....Practice .....& and you guessed it.....More Practice!
Click on the Button on the left to get the all important what you need!
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