ON Chemistry 303 Spring 2022 Homework #1 Due Tuesday, February 1 1. What mass of oxygen is in 0.500 L of air at 37C and 760 torr? This is approximately the volume of 1 human breath and body temperature. Assume the mole fraction of oxygen in the air is 0.200. Remember that the oxygen in air is in the form of o, molecules 2. What is the mean (average) speed of the O, molecules in question #1? 3. If a breath of air, with a volume of 0.500 L, is drawn into the lungs and comes to thermal equilibrium with the body at 37C while the pressure remains constant, calculate the increase in enthalpy of the air if the initial air temperature is 19C and the pressure is 1.00 atm. At a breathing rate of 12 breaths per minute, how much heat is lost in this fashion in 1 day? (See table 2B.1 on page 49 of the textbook for the heat capacity of air. Assume a constant value of the heat capacity over the temperature range of this problem.) 4. Copper metal reacts with concentrated nitric acid as shown in this chemical equation: Cu(s) + 4HNO,(aq) Cu?'(aq) + 2 NO, (aq) +2 NO2(g) + 2 H2O(1) Estimate the amount of pressure-volume work involved when 10.0 g of Cu reacts in a system open to air at a pressure of 760 torr and temperature of 25C. Neglect the volume of the solid and liquids in this reaction. 5. Using the thermodynamic tables in appendix A3.2 calculate the change in enthalpy when 10.0 g of Cu reacts according to the above equation, assuming all of the reactants and products are in their standard state. 6. How much heat is required to change 1.00 mol of methanol (CH3OH) from a liquid at 25C to a gas at 100C, at a constant pressure of 1 atm? Refer to table 2.1 on page 63 and table A3.1 on page 527 for relevant data