You are comparing a reaction that produces a chemical change and one that produces a physical change. What evidence could you use to determine which type of change is occuring?

Calculate the enthalpy of the following reaction: 4 b (s) + 3 o2 (g) → 2 b2o3 (s) given the following pertinent information: (a) b2o3 (s) + 3 h2o (g) → 3 o2 (g) + b2h6 (g), δhoa = +2035 kj (b) 2 b (s) + 3 h2 (g) → b2h6 (g), δhob = +36 kj (c) h2 (g) + latex: \frac{1}{2} 1 2 o2 (g) → h2o (l), δhoc = −285 kj (d) h2o (l) → h2o (g), δhod = +44 kj

For a patient with the following pes statement and interventions, which would be the most appropriate monitoring and evaluating data? pes statement: inadequate calcium intake related to food and nutrition related knowledge deficit as evidenced by statements that the only dietary source of calcium is milk and she believes that she is lactose intolerant. patient’s nutrition prescription is for a diet providing 1200 mg calcium per day. patient was provided with in-depth nutrition education on alternative dietary and supplement sources of calcium. a. calcium intake (at subsequent visit) b. knowledge assessment by asking patient to identify food sources from menus and shopping list (at the end of the current visit) c. serum calcium (at next visit) d. both a and b e. both a and c

If a molecule with a molecular formula of c13h18 is treated with an excess of h2 in the presence of finally divided pt metal under conditions required for maximum hydrogenation of the molecule to give a molecule with a formula c13h24, how many rings are in the molecule?