Balancing Equations Coefficient Question

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Amanda Bueno-Kling
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Balancing Equations Coefficient Question

Postby Amanda Bueno-Kling » Sun Oct 25, 2020 9:35 pm

Sometimes when I am balancing chemical equations, I end up with coefficients that are not whole numbers. For example, there are 15 mols of O on one side, and on the other side I have to add a coefficient before O2. I can't put 7.5, even though 7.5 * 2 = 15, because I know coefficients have to be whole numbers. Is the best thing to do in this case multiply every coefficient in the reaction by 2? This should preserve the ratio while making everything a whole number?

Hannah Alltucker 3L
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Re: Balancing Equations Coefficient Question

Postby Hannah Alltucker 3L » Sun Oct 25, 2020 9:43 pm

Yes, you would multiply the equation by two in order to make all coefficients whole numbers. Having whole number coefficients makes the equation easier overall to use in future steps.

Andreas Krumbein 1L
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Re: Balancing Equations Coefficient Question

Postby Andreas Krumbein 1L » Sun Oct 25, 2020 9:44 pm

Yes, you can't have a half of an atom (unless you want to experience dire consequences), and so in a molecular equation you should scale each coefficient up to the lowest whole number. (eg, 7.5 should become 15, and 2.75 should become 11). If at any point if you write a fraction as a coefficient in a molecular equation, it will be marked wrong.

Erika Sosa-Cruz 1J
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Re: Balancing Equations Coefficient Question

Postby Erika Sosa-Cruz 1J » Sun Oct 25, 2020 9:53 pm

Yes the best thing to do would be to multiply the coefficients by two because we want whole numbers, and to answer your second question it will in fact preserve the ratio.

Kelly Tran 1J
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Re: Balancing Equations Coefficient Question

Postby Kelly Tran 1J » Sun Oct 25, 2020 9:54 pm

Yes, you would multiply each coefficient by 2 since the stoichiometric coefficients must be whole numbers. In the notes for this topic, Dr. Lavelle stated how multiplying both sides of the chemical equation by a number does not affect the balance of each atom type.

Jaclyn Schwartz 1I
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Re: Balancing Equations Coefficient Question

Postby Jaclyn Schwartz 1I » Sun Oct 25, 2020 11:46 pm

Yes, that is exactly right! Using fractions and non-whole numbers makes it more difficult to solve. And when you multiply by 2 on each side, it does not unbalance the equation because you are doing it to both sides.

Andrew Yoon 3L
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Re: Balancing Equations Coefficient Question

Postby Andrew Yoon 3L » Sun Nov 01, 2020 12:40 pm

If your equation has any stoichiometric coefficients that are fractions, you need to convert them to whole numbers. Since you can't have a fraction of a compound, you need to multiply whatever number on one side to the other as well in order for it to be balanced.

John_Tran_3J
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Re: Balancing Equations Coefficient Question

Postby John_Tran_3J » Sun Nov 01, 2020 12:57 pm

To correctly balance an equation with fractions as stoichiometric coefficients, you must multiply every coefficient with the demoniator of the fraction. This action causes every coefficient (including the faction) to become a whole number.

Sukhkiran Kaur 3I
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Re: Balancing Equations Coefficient Question

Postby Sukhkiran Kaur 3I » Sun Nov 01, 2020 1:08 pm

Yes that's right, since you would use the lowest value possible that would give you whole numbers for coefficients.

abby hyman
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Re: Balancing Equations Coefficient Question

Postby abby hyman » Sun Nov 01, 2020 2:15 pm

Yes, you have the right idea about it. since you do not want a coefficient to be 15/2 you have to multiply every coefficient by 2 so they are all in whole numbers and maintain the correct ratio

Sreeram Kurada 3H
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Re: Balancing Equations Coefficient Question

Postby Sreeram Kurada 3H » Sun Nov 01, 2020 2:27 pm

Yeah I would continue doing the same thing you are doing right now since it is much easier to balance the chemical equation.

Michelle Nguyen 3F
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Re: Balancing Equations Coefficient Question

Postby Michelle Nguyen 3F » Sun Nov 01, 2020 4:01 pm

When that happens, try to multiply it to get the lowest coefficient possible. For instance, if you have 7.5, multiply it by 2 to get 15. If you have 3.33, multiply by 3 to get 10. It's important to look at the decimals to see what number you should multiply by.

Susan Chamling 1F
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Re: Balancing Equations Coefficient Question

Postby Susan Chamling 1F » Mon Nov 02, 2020 12:00 am

Yes, you would want to multiply your coefficients by the same number in order to get whole ratios. As long as you preserve the ratio, multiplying the coefficients is fine.

Annette Fishman
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Re: Balancing Equations Coefficient Question

Postby Annette Fishman » Mon Nov 02, 2020 8:22 am

Yes, you should multiply your coefficients by the same number in order to get whole ratios. That number should be the smallest coefficient possible, or you'll need to simplify. For example, if the coefficient is 1.5, you'd want to multiply by 2. If 3.33, multiply by 3. When you put it in fraction for it's easier to see - 3/2 *2 = 3. Don't forget to preserve the ratio of the reactants and products, and you'll be good :)

Gicelle Rubin 1E
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Re: Balancing Equations Coefficient Question

Postby Gicelle Rubin 1E » Sat Nov 07, 2020 6:26 pm

As everyone has said, as long as you multiply both by the same number, you should be fine! :)

Bai Rong Lin 2K
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Re: Balancing Equations Coefficient Question

Postby Bai Rong Lin 2K » Sun Nov 08, 2020 11:24 pm

Amanda Bueno-Kling 2L wrote:Sometimes when I am balancing chemical equations, I end up with coefficients that are not whole numbers. For example, there are 15 mols of O on one side, and on the other side I have to add a coefficient before O2. I can't put 7.5, even though 7.5 * 2 = 15, because I know coefficients have to be whole numbers. Is the best thing to do in this case multiply every coefficient in the reaction by 2? This should preserve the ratio while making everything a whole number?

you just multiply the coefficient by to in order to reach a whole number for the final balance equation.


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