Check my answers ? 1. which of the following is a correctly written thermochemical equation? nh4cl nh4+ + cl 2c8h18 + 25o2 16co2 + 18h2o, h = 5,471 kj/mol fe (s) + o2 (g) fe2o3 (s), h = 3,926 kj –> c3h8 (g) + 5o2 (g) 3co2 (g) + 4h2o (l), h = 2,220 kj/mol 2. how does a phase change affect a thermochemical equation? it alters the moles of reactants. –> it can affect the (delta) h value. it alters the products. it affects the balance of the equation. 3. for the reaction ch4 (g) + 2o2 (g) co2 (g) + 2h2o (l), h = 890 kj, what will be the change in enthalpy when 3 moles of methane react in excess oxygen? 890 kj –> 2.67 × 103 kj +890 kj +2.67 × 103 kj 4. in which of the following thermochemical equations would the h be considered a heat of solution? nh4cl (s) nh4+ (aq) + cl (aq), h = + 14.8 kj/mol 2c8h18 (l) + 25o2 (g) 16co2 (g) + 18h2o (l), h = 5,471 kj/mol –> 4fe (s) + 3o2 (g) 2fe2o3 (s), h = 3,926 kj c3h8 (g) + 5o2 (g) 3co2 (g) + 4h2o (l), h = 2,220 kj/mol 5. for the following reaction at stp, how much heat will be required to produce 63 l of no? (at stp, one mole of any gas occupies 22.4 l.) n2 (g) + o2 (g) 2no (g), h = 180.5 kj +63 kj +127 kj –> +254 kj +508 kj


1. I think you have chosen the correct answer, the state of the reagents and products is in the equation. 2. I think you chose the right answer. 3. I think you also chose the right answer. Assuming that the Hrxn is written as kJ per mol CH4 4. The heat of the solution is the enthalpy change associated with dissolving a solution in a solvent. I think the first option is the right one. 5. I think you chose the right answer.