Ethanol is added to gasoline because the oxygen it contains improves gasoline's burning efficiency. Its combustion reaction is given below. CH3CH2OH(l) + 3O2(g) → 2CO2(g) + 3H2O(g) ∆H = - 1236 kJ a) Is this an exothermic or endothermic reaction? b) If 15.3 grams of pure ethanol is completely converted to products, calculate how much heat is absorbed or released, in: (1) kJ and in (2) kcal c) If 42.7 g of water vapor is produced, how much heat, in kJ, is absorbed or released?

13. calculate the initial concentration (before precipitation) of carbonate ions after the addition of each 0.05 ml of solution b to the 1.00 l beaker of solution a. divide the work among group members and write the answers in the table in model 3. assume the volume change as solution b is added is negligible. 14. notice the initial concentrations of zn2+ - and cu2+ in the table in model 3. a. explain how these were obtained from the data in model 2. b. as solution b is added and precipitates form, do these initial concentrations change? 15. use the data in model 2 to indicate the presence of precipitate (either znco3 or cuco3) after each 0.05 ml addition of solution b in model 3. 16. use the initial concentrations of carbonate ions and zinc ions to calculate the reaction quotient, qsp for the zinc carbonate scenarios in model 3. divide the work among group members and write the answers in the table in model 3. 17. use the initial concentrations of carbonate ion and copper(ii) ions to calculate the qsp for the copper(ii) carbonate scenarios in model 3. divide the work among group members and write the answers in the table in model 3.

What are the primary responsibilities of a chemical engineer involved in "r& d"? develop large scale manufacturing operations discover new products and processes training of new chemists determine products needed by consumers

The element that has the greatest electronegativity is