24.  (WCSU25.[x]) Strategies to convert methane to methanol…

24.  (WCSU25.[x]) Strategies to convert methane to methanol may be useful to produce quantities of methanol for use as a fuel alternative to gasoline. a.  (4 points) Write a chemical equation where ΔHf = ΔHrxn for the formation of methanol (CH3OH) b.  (4 points) If the heat of formation of 1 mol of CH3OH is -201.3 kJ, calculate the heat exchanged when 43 g are formed?   Enter the heat calculated in part b below.

20. (WCSU25.[x], 8 points) You are developing a new fluoride…

20. (WCSU25.[x], 8 points) You are developing a new fluoride-containing mouthwash.  Rather than using NaF, you decide to use SnF2.  This should save money since tin fluoride is cheaper and is shown to prevent cavities in a number of studies. Calculate the mass of SnF2 (MW = 156.69 g/mol) needed to prepare 500 mL of a mouthwash with a 0.01 M fluoride ion concentration? Enter the mass needed below.

(WCSU25) Arrange the following in order of increasing…….

(WCSU25) Arrange the following in order of increasing….         smallest/lowest –> largest/highest Example:  Radius Cs Rb Li Li             Rb           Cs Atomic radius P Mg F [drop1] < [drop2] < [drop3] Bond strength C=C C-C C≡C [drop4] < [drop5] < [drop6] Melting point NaCl CH4 H2O [drop7] < [drop8] < [drop9] Ionization energy Cl P Na [drop10] < [drop11] < [drop12] Bond angle HCN NH3 H2O [drop13] < [drop14] < [drop15] Bond polarity C-F C-N C-H [drop22] < [drop23] < [drop24] Energy 3s 2s 3p [drop16] < [drop17] < [drop18] Energy UV light X-rays micro waves [drop19] < [drop20] < [drop21]