1. Given the following thermochemical data at 25°C and 1 atm pressure, 3 02(g) + 2B(s) → B2O3(s) AH°=-1264 kJ 03(g) + 2B(s) → B2O3(s) AH° = -1406 kJ determine AH° for the following reaction at 25°C and 1 atm pressure. 203(g) → 302(g)

Using the data in Appendix G, calculate the standard enthalpy change for each of the following reactions: (a) Si(s)+2F2(g)SiF4(g) (b) 2C(s)+2H2(g)+O2(g)CH3CO2H(l) (c) CH4(g)+N2(g)HCN(g)+NH3(g) ; (d) CS2(g)+3Cl2(g)CCl4(g)+S2Cl2(g)

An industrial process for manufacturing sulfuric acid, H2SO4, uses hydrogen sulfide, H2S, from the purification of natural gas. In the first step of this process, the hydrogen sulfide is burned to obtain sulfur dioxide, SO2. 2H2S(g)+3O2(g)2H2O(l)+2SO2(g);H=1124kJ The density of sulfur dioxide at 25C and 1.00 atm is 2.62 g/L, and the molar heat capacity is 30.2 J/(mol C). (a) How much heat would be evolved in producing 1.00 L of SO2 at 25C and 1.00 atm? (b) Suppose heat from this reaction is used to heat 1.00 L of the SO2 from 25C to 500C for its use in the next step of the process. What percentage of the heat evolved is required for this?

How much heat is produced when loo mL of 0.250 M HCl (density, 1.00 g/mL) and 200 mL of 0.150 M NaOH (density, 1.00 g/mL) are mixed? HCl(aq)+NaO(aq)NaCl(aq)+H2O(l)H298=58kJ If both solutions are at the same temperature and the heat capacity of the products is 4.19 J/g C, how much will the temperature increase? What assumption did you make in your calculation?