Question

Please, I need the answer for all questions.

In the electrolysis experiment similar to the one employed in this experiment; a student observed that his unknown metal anode lost 0.238 grams while a total volume of 94.50 mL of hydrogen was being produced.

The temperature of the solution was 25 °C and the barometric pressure was 740 mm Hg.

The vapor pressure of water at 25 °C is 23.8 mm Hg.

1. What is the pressure of the hydrogen gas in atmospheres?

                                                                                                                

2. What is the volume of hydrogen gas in liters?

3. Calculate the number of moles of hydrogen gas using the ideal gas law (For checking yourself, the answer is between 0.003 and 0.004 moles)

4. One mole of H2 requires passage of ______ Faradays

5. Number of Faradays passed = ______________

6. EM = ____________________

7. The student was told the metal was oxidized to a +2 oxidation state. What is the metal in the anode?

Answer 1

1. Pressure of H2 = . Barometric pressure - Vapor pressure of waler - (7402318) mm Hg = 716.2 mm Hg = (7163) atm [3" 760 mm Hg =ı atm] = 0.9424 atu 2. volume of H₂ gas = 94.50 ml = 0.0945 L 3. PV = nRT AP=0.9424 atin op n = PV = 0.9424 X0-0945) V-0.0945 L umina T 0.0821 * 298 R=0.0821 L-ammud K T=(25+273) -298 =0.00364. mol. . No. of moles of H₂ produced =0.00364 4.. 2H+ +2e H2 I mot H2 = zeg, wt of Hydrogen = 2F i mol of Hy requires passage of 2 Farady 5. No. of Faraday passed =(0.00364+2) = 0.00728F. RT 6. = EMX Q R or 0.238" = EM X_ 0.00728 F - EM - Equivalent mass of metal Or EM = 19:05-) = 32.69 7. Atomic mass of metal = EMX oxidabion state (valency) = 3269x2. = 65.38 . The metal is zine (Zn) in the anode [atomi mass of Zn = 65.377