sign changes in bond enthalpy

[Clara Cho 2K]

How do you know when to change the sign of a bond enthalpy?

[Fiona Latifi 1A]

Bond enthalpy is positive when bonds are being broken because this process requires energy. Bond enthalpy is negative when bonds are being formed because this process releases energy.

[Sahil Jog 1F]

When you're given the bond enthalpies on a table, you would make the enthalpies negative when bonds are formed (the products). This is because the net enthalpy of a reaction is the enthalpies of bonds broken minus the bonds formed.

[Rosa Munoz 2E]

Energy is required to break bonds so it is positive. When bonds are formed it is negative.

[Nuoya Jiang]

Energy is required when we break a bond, so the sign should be positive. When bonds form, it releases energy, and so the sign should be negative.

[Vincent Leong 2B]

you can refer to hess's law to explain why delta H is positive or negative. The formula involving the summation of products minus the summation of reactants should indicate where heat lies in the reaction and whether bonds are being broken or formed.