Identifying endothermic vs exothermic

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405318478
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Identifying endothermic vs exothermic

Postby 405318478 » Sun Jan 19, 2020 4:57 pm

If a problem doesn't specifically state if it is endothermic or exothermic, how do we determine which it is based off the stoichiometric equation?

Elena Bell 1C
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Re: Identifying endothermic vs exothermic

Postby Elena Bell 1C » Sun Jan 19, 2020 5:04 pm

A reaction is exothermic if the products have more energy than the reactants, and it is endothermic if the reactants have more energy than the products. Usually, the reaction would give you a deltaH value if it is asking about temperature. DeltaH would be negative if the reaction is exothermic and positive if it is endothermic.

Eugene Chung 3F
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Re: Identifying endothermic vs exothermic

Postby Eugene Chung 3F » Sun Jan 19, 2020 5:06 pm

Elena Bell 1C wrote:A reaction is exothermic if the products have more energy than the reactants, and it is endothermic if the reactants have more energy than the products. Usually, the reaction would give you a deltaH value if it is asking about temperature. DeltaH would be negative if the reaction is exothermic and positive if it is endothermic.


This because energy is absorbed in form of heat in an endothermic reaction and energy is released in exothermic reaction.
Endothermic absorbs heat, and exothermic produces heat.

san_2F
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Re: Identifying endothermic vs exothermic

Postby san_2F » Sun Jan 19, 2020 5:40 pm

When delta H is negative, it's exothermic and when delta H is positive, the reaction is endothermic.

Noe BM 1J
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Re: Identifying endothermic vs exothermic

Postby Noe BM 1J » Sun Jan 19, 2020 9:41 pm

If delta H is negative, it means that the reaction is exothermic (it releases energy). If delta H is positive, the reaction is endothermic (it requires energy).

Ruth Glauber 1C
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Re: Identifying endothermic vs exothermic

Postby Ruth Glauber 1C » Sun Jan 19, 2020 11:42 pm

Check if the products have more energy than the reactants to decide if its exothermic!

Sanjana K - 2F
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Re: Identifying endothermic vs exothermic

Postby Sanjana K - 2F » Mon Jan 20, 2020 3:26 am

You can also look at bond enthalpies or use Hess's Law to figure out the total energy on the reactants and products side or the energy needed to form/break the bonds and if delta H < 0, it's exothermic and if delta H > 0, it's endothermic.

Mitchell Koss 4G
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Re: Identifying endothermic vs exothermic

Postby Mitchell Koss 4G » Mon Jan 20, 2020 7:58 am

They will need to give you a delta H, so it it is positive, reaction is endothermic, but if it is negative, it is exothermic.


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