Consider a sample containing 5.00 moles of a monatomic ideal gas that is taken from state A to state B by the following two pathways: Pathway one: PA 5 3.00 atm 1 PC 5 3.00 atm VA 5 15.0 L 88n VC 5 55.0 L 2 PB 5 6.00 atm 88n VB 5 20.0 L Pathway two: PA 5 3.00 atm 3 PD 5 6.00 atm VA 5 15.0 L 88n VD 5 15.0 L 4 PB 5 6.00 atm 88n VB 5 20.0 L For each step, assume that the external pressure is constant and equals the final pressure of the gas for that step. Calculate q, w, DE, and DH for each step, and calculate overall values for each pathway. Explain how the overall values for the two pathways illustrate that DE and DH are state functions, whereas q and w are path functions.
Week of 2/29- 3/4 ENERGY IN CHEMISTRY Energy is the ability to do work. It is neither created nor destroyed, simply transferred. Kinetic energy and potential energy are present in chemical bonds SOURCES OF KINETIC ENERGY IN CHEMICAL SYSTEM -particles move and rotate through space -bonds vibrate -electrons move around nucleus SOURCES OF POTENTIAL ENERGY IN CHEMICAL SYSTEM -bonded atoms attract and repel -the attraction between nucleus and electrons, also the repulsion between electrons and electrons - Attraction b/w nucleus and shared electrons During chemical reactions, change occurs in BONDING - Changes in the way atoms are bonded involve changes in chemical potential energy - System- the reaction itself - Surroundings- imme
