Questions: Question 12 3.35 Points If we touch a flask after urea was in the water in the flask, we will feel the flask is now cooler than it was before the urea was added. What can we say about this reaction between potassium and the water? A It is an endothermic reaction. (B) The value of ΔE is negative. C Heat from surrounds is absorbed by the system (D) The value for q in ΔE=q+w is negative (E) All the above are true F Only A and C are true

Solution Steps

When urea is dissolved in water and the flask feels cooler, it indicates that the reaction absorbs heat from the surroundings. This is characteristic of an endothermic reaction.

• Option A: It is an endothermic reaction. This is true because the reaction absorbs heat, making the surroundings cooler.
• Option B: The value of \(\Delta E\) is negative. This is not necessarily true for an endothermic reaction. \(\Delta E\) depends on both heat and work, and we don't have information about work done.
• Option C: Heat from the surroundings is absorbed by the system. This is true for an endothermic reaction.
• Option D: The value for \(q\) in \(\Delta E = q + w\) is negative. For an endothermic process, \(q\) is positive because the system absorbs heat.
• Option E: All the above are true. This is incorrect because not all statements are true.
• Option F: Only A and C are true. This is correct based on the analysis above.

Final Answer