What is the product for the following three-step reaction sequence? 1. Br₂ hv 2. t-BuOK, t-BuOH, heat 3. Cold KMnO4, NaOH, H₂O CHO OH CH x8888 I OA. I OB. IV Oc. v OD. III CHO II он CO₂H III IV V -OH OE. I

The only stress (change) that also changes the value of K is a change in temperature. For an exothermic reaction, how does the equilibrium position change as temperature increases, and what happens to the value of K? Answer the same questions for an endothermic reaction. If the value of K increases with a decrease in temperature, is the reaction exothermic or endothermic? Explain.

For a precipitation reaction to be useful in a gravimetric analysis, the product of the reaction must be insoluble. Is Kc1,1 or 1 for a useful precipitation reaction?

Hydrogen for use in ammonia production is produced by the reaction CH4(g)+H2O(g)750oCNicatalystCO(g)+3H2(g) What will happen to a reaction mixture at equilibrium if a. H2O(g) is removed? b. the temperature is increased (the reaction is endothermic)? c. an inert gas is added to a rigid reaction container? d. CO(g) is removed? e. the volume of the container is tripled?

12.67 Hydrofluoric acid is a weak acid used in the building industry to etch patterns into glass for elegant windows. Because it dissolves glass, it is the only inorganic acid that must be stored in plastic containers. A 0.1 M solution of HF has a pH of 2.1. Calculate [Hj0"| in this solution.

. Before two molecules can react, chemists envision that the molecules must first collide with one another. Is collision among molecules the only consideration for the molecules to react with one another?

The following is a thought experiment. Imagine that you put a little water in a test tube and add some NaF crystals. Immediately after you add NaF, you observe that the crystals begin dissolving. The quantity of solid NaF decreases, hut before long, it appears that no more NaF is dissolving. The solution is saturated. The equation for the dissolution of NaF in water is NaF(s) —* Na (aq) + F~(aq). As NaF dissolves, what do you think happens to the rate of dissolution? Describe w hat is occurring on the molecular level. Assume that the reverse reaction, Na+(aq) + F“(aq) —* NaF(s), also occurs as the crystal dissolves. In other words, both dissolution and precipitation are taking place. When it appears that there is no more change in the quantin’ of NaF dissolving (the solution is saturated), w hat has happened to the rates of the forward and reverse reactions? Explain your answer.

Sodium chloride is added to water (at 25C) until it is saturated. Calculate the Cl concentration in such a solution. Species G(kJ/mol) NaCl(s) 384 Na+(aq) 262 Cl(aq) 131

The following reaction occurs in pure water: H2O(l)+H2O(l)H3O+(aq)+OH-(aq) which is often abbreviated as H2O(l)H+(aq)+OH-(aq) For this reaction, G = 79.9 kJ/mol at 25C. Calculate the value of G for this reaction at 25C when [OH] = 0.15 M and [H+] = 0.71 M.

12.100 A reaction important in smog formation is O3(g)+NO(g)O2(g)+NO2(g)K=6.01034 (a) If the initial concentrations are [O3]=1.0106M,[NO]=1.0105M,[NO2]=2.5104M, and [O2]=8.2103M , is the system at equilibrium? If not, in which direction does the reaction proceed? (b) If the temperature is increased, as on a very warm day, will the concentrations of the products increase or decrease? (HINT: You may have to calculate the enthalpy change for the reaction to find out if it is exothermic or endothermic.)