Wednesday, July 4, 2007

Where did she get her degree...

Today, Ms Ng and I continued our Chicken Breast theory war. I looked her up after chemistry lecture and we started arguing. She said
"when there is a rise in thermometer reading, the heat change is negative."
"No. The thermometer can only measure the change in temperature of the surrounding, not the internal energy content of the reactants. Therefore when there is a rise in temperature, heat change is positive (because it is with respect to the surrounding that the thermometer is measuring)"
"Ah, Zheng Han, you are confused."
"NO! YOU! are confused!!"

I strongly believe that when making a report with respect to the reading you got off the thermometer, when you write a vague statements like "heat change", it is rightfully assumed to be the heat change in the substance that the thermometer (the instrument which you got the reading from) is measuring. In this case the surrounding solvent, not the reactants!! Thermometers cannot measure internal heat content of a molecule! Therefore is it not true that the temperature of the solvent rises because it has absorbed energy from the reacting agents? More heat energy = higher temperature! When you have more energy, it is true that the change in energy is a positive, is it not?!

She told me to go check the textbooks by Ramdens. Claims that they are following closely to the syllabus. Or rather the notes we were getting were mostly similar to the textbooks. So i did check it out. Indeed, heat change is positive when the temperature of the solvent rises because it is referring to the solvent (the substance the thermometer is measuring!)! And all the textbooks I found in the library needed to use theoretical explanations to change the positive heat change to a negative enthalpy change!!! Omg... where did she get her degree

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