Negative Square Root solving an ICE box

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Payton Kammerer 2B
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Negative Square Root solving an ICE box

Postby Payton Kammerer 2B » Sat Jan 25, 2020 11:53 pm

While trying to solve an ICE box, I was using the quadratic formula and got a negative number inside of the square root term. What am I supposed to do with this? Is it supposed to be possible, or have I definitely made a mistake elsewhere?

Jielena_Bragasin2G
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Re: Negative Square Root solving an ICE box

Postby Jielena_Bragasin2G » Sun Jan 26, 2020 12:20 am

When using the quadratic formula, you are supposed to get two terms from the equation. It is not just a negative square root, it is a plus or minus (+/-) meaning the square root value should be added and subtracted from the -B value, which gives you two different solutions. We always pick the solution that is positive and/or no greater than the initial molar concentration given.

Naneeta Desar 1K
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Re: Negative Square Root solving an ICE box

Postby Naneeta Desar 1K » Sun Jan 26, 2020 12:21 am

Having a negative square root would not make sense in the context of the problem therefore you should check your previous work to see if you have made a mistake.

BritneyP- 2c
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Re: Negative Square Root solving an ICE box

Postby BritneyP- 2c » Sun Jan 26, 2020 1:16 am

Usually you do not get a negative square root term, but you get a negative number or a positive number. You ignore the negative number for the positive number when you are looking for the concentration .

RobertXu_2J
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Re: Negative Square Root solving an ICE box

Postby RobertXu_2J » Sun Jan 26, 2020 1:37 am

If you got a negative number, you did something wrong.

Jasmine Kim 1L
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Re: Negative Square Root solving an ICE box

Postby Jasmine Kim 1L » Sun Jan 26, 2020 11:11 am

Usually the math is pretty straightforward in the chemistry problems we get, so if you got a negative number inside the square root, then you probably did something wrong.

KnarGeghamyan1B
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Re: Negative Square Root solving an ICE box

Postby KnarGeghamyan1B » Sun Jan 26, 2020 11:12 am

When this happens to me, it's because I usually forget to square the b inside the square root, which leads to a negative inside. You should not get a negative value inside the square root.

Emily Lo 1J
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Re: Negative Square Root solving an ICE box

Postby Emily Lo 1J » Sun Jan 26, 2020 4:05 pm

If you got a negative number inside the square root, I would re-check the calculations inside of the square root. You shouldn't be getting a negative because that would result in an imaginary number.

Anish Natarajan 4G
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Re: Negative Square Root solving an ICE box

Postby Anish Natarajan 4G » Sun Jan 26, 2020 8:24 pm

You probably shouldn't be getting a negative seeing as how the Acid/Base on the product side becomes a negative term when you set the entire equation equal to 0. Remember that it's b^2-4ac so the two negatives should cancel out

Callum Guo 1H
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Re: Negative Square Root solving an ICE box

Postby Callum Guo 1H » Sun Jan 26, 2020 9:05 pm

Trying doing the opposite of what you did (i.e. since its -b plus or minus ... , try minus if you did plus and plus if you did minus)

Shimei_2F
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Re: Negative Square Root solving an ICE box

Postby Shimei_2F » Sun Jan 26, 2020 9:07 pm

Usually, you shouldn't get a negative number inside the square root. Outside the square root, it can be positive and negative.

jisulee1C
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Re: Negative Square Root solving an ICE box

Postby jisulee1C » Sun Jan 26, 2020 9:11 pm

When solving the quadratic formula, two answers are usually calculated. You should use the positive x value calculated for concentration because concentration itself cannot be a negative value.

Hannah Pham
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Re: Negative Square Root solving an ICE box

Postby Hannah Pham » Sun Jan 26, 2020 10:32 pm

You might have made a mistake because you should not have a negative number inside the square root. However, the overall answer when solving the quadratic formula can be positive and negative.

Ashley Nguyen 2L
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Re: Negative Square Root solving an ICE box

Postby Ashley Nguyen 2L » Sun Jan 26, 2020 11:22 pm

You should not receive a negative square root. You most likely did something wrong in the math and should check your work


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