Thermodynamics

1. 5.30 moles of gas, initially at 25 degrees celcius and 5.00 atm pressure, was allowed to expand adiabatically( with no heat exchange between systen and surroundings) against a constant external pressure of 1.50 atm until the initial volume had trebled. The heat capacity of the gas was known to be 37.1 J/ degree celuius mol Determine the following 1. Inital volume 2. The finial volume 3. w 4. q 5. change in Energy 6. The final temperature of the gas 2. Would it be feasible to make ethanol, C2H5OH, by the following reaction ( under standard conditions and 25 degrees C) C2H4(g) + H2O(l) --------- C2H5OH(l) 3. Calculate the molar entropy of vapori... click for more

Electrochemistry

1. Calculate the standard stat emf, fancy E, change in G, and K at 25 degrees celcus for the following reaction 2Na(s) + 2H20(l) --------- 2NaOH(aq) + H2(g) standard reduction potentals: Na(positive 1) + e- ---------Na -2.71V 2H20 + 2e- ------------H2 + 2OH- - .83V 2. What mass of Pb would be deposited by electrolysis of and aqueous solution of lead(II) nitrate using a current of 100 amps of 8.00 hours? 3. Draw a complete galvanic cell in which the electrodes are a nickel bar dipping into a 0.100M solution of Ni(positive 2) and a manganese bar dipping inot a 0.500 M soulution of Mn(positive 2). Label all the parts of the cell and indicate the di... click for more

Rates and electrochemistry

The numerical value of the rate constant for the gaseous reaction 2N2O5------- 4NO2+ O2 was found to be 5.8*10-4. The initial concetration of N205 was 1.00mol/L. Assuming all measurements are recorded in seconds, determine the tim required for the reation to be 60% complete if the reaction is second order. 2. For each of the following cells write a balaced vell redox equation and calculate E(upper little circle) a. Ag(s) / Ag2S / S(- 2)(aq) // HClO(aq), H(+ 1)(aq) / Cl2(g) / Pt b. Pt / Cr2O7(- 2)(aq), Cr(+3)(aq), H(+1) // Cl(-1)(aq) / Cl2(g) / Pt c. Fe / Fe (+3)(aq) // Cl(-1) / Hg2Cl2(s) / Hg(l) Ag2S(s) + 2e- -------------- 2 Ag(s) + S(-2... click for more

Rates and electrochemistry

1. Step 1: Cl2 ------ 2Cl (fast) Step 2: CHCl3 + Cl -------- CCl3 + HCl (slow) Step 3: CCl3 + Cl ------------CCl4 (fast) Identify the rate determining step, reaction intermediates and the experimental rate law (intermediates can not be in the rate law) 2. For the half-reaction XeF2(aq) + 2H(+1)(aq) + 2e- ----------- Xe(g) + 2HF(aq) E(little circle) = +2.64 a). calculate the (triange)G for the reaction XeF2(a) + H2(g)-------------Xe(g) + 2HF(aq) b). given that the free energy of formation, (triangle)Gf(little circle), of HF(aq) is -276KJ/mol calcuate (triange)Gf fo XeF2(aq) 3. Acidic MnO4(-1) solution reacts with ethanol,... click for more

Thermodynamics

1. At 25 degees C, (triange)H(little o) for the combustion of liquid octane, C8H18(l) to form CO2(g) and H2O(l) is -5471kJ/mol. Calculate (triangle)E(little o) for this reaction at 25 degrees C. 2. The molar heat of vaporization of benzene, C6H6, at 1 atm is 30.8 kJ/mol. the boiling point of benzene at 1 atm is 78.3 degree C. Calculate the enthropy change when 11.5g of benzene boils at the temperature. 3. The heat capacity of a bomb calorimeter, is 87.5kJ/K ( this value is for the total heat capacity including that of the water jacket around the reaction chamber). If 67.2g of methane(g) is combusted under such reaction conditions, what will be the increase in temperature on the ... click for more