9-5. Determine Avogadro's number. Atomic weight of copper is 63.546 g/mol. 9-6. What is the percent error in this measurement of Avogadro's number? 9-7. It is also possible in principle to collect the hydrogen gas evolved and use its weight to determine Avogadro's number. Calculate the weight of evolved hydrogen gas. Is this determination of Avogadro's number from the weight of evolved hydrogen practical? Problem 10: Enthalpy, entropy, and stability All chemical changes in living and non-living systems obey laws of thermodynamics. The equilibrium constant of a given reaction is determined by changes in Gibbs free energy, which is in turn determined by enthalpy change, entropy change, and the temperature. 10-1. Fill in the blanks (a-f) with all that apply from the following: equilibrium constant, Keq entropy change, ΔS enthalpy change, ΔH free energy change, ΔG a. strongly temperature-dependent ( ) b. closely related to bond strength ( ) c. measure of change in randomness ( ) d. related to the quantity of reactants and products ( ) e. measure of spontaneity of a reaction ( ) f. measure of heat released or absorbed ( ) The following equilibrium exists in the vapor phase dissociation of molecular addition compounds of donor molecules, D, and boron compounds, BX3. + BX3(g) DBX3(g) ↔ D(g) Kp = [D][BX3]/[D·BX3]
9-5. Determine Avogadro's number. Atomic weight of copper is 63.546 g/mol. 9-6. What is the percent error in this measurement of Avogadro's number? 9-7. It is also possible in principle to collect the hydrogen gas evolved and use its weight to determine Avogadro's number. Calculate the weight of evolved hydrogen gas. Is this determination of Avogadro's number from the weight of evolved hydrogen practical? Problem 10: Enthalpy, entropy, and stability All chemical changes in living and non-living systems obey laws of thermodynamics. The equilibrium constant of a given reaction is determined by changes in Gibbs free energy, which is in turn determined by enthalpy change, entropy change, and the temperature. 10-1. Fill in the blanks (a-f) with all that apply from the following: equilibrium constant, Keq entropy change, ΔS enthalpy change, ΔH free energy change, ΔG a. strongly temperature-dependent ( ) b. closely related to bond strength ( ) c. measure of change in randomness ( ) d. related to the quantity of reactants and products ( ) e. measure of spontaneity of a reaction ( ) f. measure of heat released or absorbed ( ) The following equilibrium exists in the vapor phase dissociation of molecular addition compounds of donor molecules, D, and boron compounds, BX3. DBX3(g) ↔ D(g) + BX3(g) Kp = [D][BX3]/[D·BX3]
IChO38KR2006PP.docx