A gas is confined to a cylinder under constant atmospheric pressure, as illustrated in Figure 5.4. When 0.49 kJ of heat is added to the gas, it expands and does 214 J of work on the surroundings. What are the values of \(\Delta H\) and \(\Delta E\) for this process?
Text Transcription:
\Delta H
\Delta E
Step 1 of 5) A gas is confined to a cylinder under constant atmospheric pressure, as illustrated in Figure 5.4. When 0.49 kJ of heat is added to the gas, it expands and does 214 J of work on the surroundings. What are the values of ΔH and ΔE for this processTo understand better the notion of effective nuclear charge, we can use an analogy of a light bulb with a frosted glass shade (Figure 7.2). The light bulb represents the nucleus, and the observer is the electron of interest, which is usually a valence electron. The amount of light that the electron “sees” is analogous to the amount of net nuclear attraction experienced by the electron. The other electrons in the atom, especially the core electrons, act like a frosted glass lampshade, decreasing the amount of light that gets to the observer. If the light bulb gets brighter while the lampshade stays the same (Z increases), more light is observed. Likewise, if the lampshade gets thicker (S increases), less light is observed. We will find it helpful to keep this analogy in mind as we discuss trends in effective nuclear charge.
