Hf < 0 implies which of the following?
A. The temperature decreases
B. The temperature remains the same
C. A bond-forming process
D. A bond-breaking process
I think the answer is a.
Do you mean delta Hf? If dHf<0 doesn't that mean dHf = negative and doesn't that mean it is exothermic and wouldn't that mean it gets hotter?
The answer is C
Actually, the correct answer is D. Hf < 0 implies a bond-breaking process. When the enthalpy change (Hf) is negative, it means that energy is released when the bonds are broken. Therefore, option D is the correct answer.
To determine the correct answer, we need to understand what the symbol "Hf" represents. In this context, "Hf" refers to the enthalpy of formation. The enthalpy of formation (Hf) is the amount of energy released or absorbed when one mole of a compound is formed from its constituent elements in their standard states.
The enthalpy of formation can be positive or negative. A positive value of Hf (>0) indicates that energy is absorbed during the formation of the compound, while a negative value of Hf (<0) indicates that energy is released.
Now let's consider the options:
A. The temperature decreases: This option is incorrect because the sign of Hf does not directly indicate the change in temperature.
B. The temperature remains the same: This option is incorrect for the same reason as option A.
C. A bond-forming process: This option is incorrect because the sign of Hf does not directly indicate whether a bond-forming process is occurring.
D. A bond-breaking process: This option is correct. A negative value of Hf (<0) indicates that energy is released, which corresponds to a bond-breaking process.
Therefore, the correct answer is D, "A bond-breaking process," as a negative value of Hf implies a bond-breaking process.