A scientist records the variation of potential energy with center-to-center distance…
CHEMISTRY · Multi-part · AP · Chemistry · Compound Structure and Properties · Compound Structure and Properties
Problem
A scientist records the variation of potential energy U with center-to-center distance r for two different interactions experienced by atoms in a sample.
• Curve A reaches a minimum value of −5kJ mol−1 at r=3.5A˚.
• Curve B reaches a minimum value of −420kJ mol−1 at r=1.0A˚.
Assume the sample initially exhibits only the interaction described by curve A. After the sample is subjected to ultraviolet radiation, the interaction described by curve B predominates.
Use the information above to answer the following questions.
(1) Interpret what physical situation each curve (A and B) represents with respect to the nature of the interaction between atoms.
(2) Using the quantitative information provided, explain why the interaction represented by curve B is classified differently from that represented by curve A.
(3) Determine whether the change induced by ultraviolet radiation is best described as a physical change or a chemical change. Provide a clear justification grounded in the data.
(4) Predict one observable macroscopic property of the sample that would be expected to change as a consequence of the shift from interaction A to interaction B, and explain why that change would occur.