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Bond Angles

Posted: Thu Jan 31, 2019 9:57 pm
by Jasmin Argueta 1K
Why is it that when bonds are formed we place a negative in front of the value? This is in regards to calculating enthalpy through bond angles in lecture.

Re: Bond Angles

Posted: Thu Jan 31, 2019 10:05 pm
by Tuong-Minh Tran 1C
In enthalpy, the energy released by an exergonic reaction is represented by a negative value (since enegy in the system is lost), while the energy required to perform an endergonic reaction is represented by a positive value (because energy is added to the system). It happens to be that the formation of bonds is exergonic, so we place a negative in front of the value.

Re: Bond Angles

Posted: Sat Feb 02, 2019 5:28 pm
by Meigan Wu 2E
Energy is required to break bonds (positive enthalpy change), while energy is released to form bonds (negative enthalpy change).

Re: Bond Angles

Posted: Sat Feb 02, 2019 9:16 pm
by Porus_Karwa_2E
The formation of bonds is exothermic, thus we place a negative sign.

Re: Bond Angles

Posted: Sat Feb 02, 2019 10:00 pm
by Harshita Talkad 4L
Forming bonds releases energy, so the negative sign represents the loss of energy from the system.

Re: Bond Angles

Posted: Sat Feb 02, 2019 10:40 pm
by ran2000
Bond formation is exothermic while bond breaking is exothermic. Hence, when bonds are formed, since they release energy, we put a negative sign before the values.