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Physical Chemistry
which assembly of thermally equilibrated molecules has the more even distribution of molecules between the two lowest vibrational energy:a)O2 molecules at 300K or b)CO molecules at 1000K.
Assume that both molecules behave as harmonic oscillators, with the ground state vibrational frequencies for O2 and CO being 4.67x10^13 and 6.43x10^13 s^-1, respectively.
Assume that both molecules behave as harmonic oscillators, with the ground state vibrational frequencies for O2 and CO being 4.67x10^13 and 6.43x10^13 s^-1, respectively.
Physical Chemistry
____ Mg + ____O2 à ____MgO
Physical Chemistry
1. Calculate the efficiency of a steam engine working at a temperature 573 K assuming the temperature of the surrounding as 298 K.
2. How much useful work can be done by carnot engine working between 0°C and 100°C if the heat supplied is 1900kJ.
3. Calculate the amount of heat supplied to a carnot cycle working between 368K and 288K if maximum obtain is 895J.
2. How much useful work can be done by carnot engine working between 0°C and 100°C if the heat supplied is 1900kJ.
3. Calculate the amount of heat supplied to a carnot cycle working between 368K and 288K if maximum obtain is 895J.
Physical Chemistry
1.21 g of ethanol, C2H5OH, was burned in a spirit burner. The heat produced raised the temperature of 400 g of water placed in a beaker above the flame from 17.0 oC to 29.9 oC. (i) Calculate the enthalpy change, in kJ mol-1, for the reaction taking place. (ii) State four reasons why this value is not equal to – 1371 kJ mol-1 which is the data book value for the standard enthalpy of combustion of ethanol.
Physical Chemistry
A student determined the enthalpy change for the reaction:
CuSO4(aq) + Zn(s) → Cu(s) + ZnSO4(aq) She placed 50 cm3 of 0.140 mol dm-3 copper
sulfate solution in a polystyrene cup and recorded the temperature for two minutes before adding an excess of zinc powder. She continued stirring and taking the temperature for a further fifteen minutes to produce the graph on the right.
(i) Determine the temperature increase if there had been no heat lost to the surroundings and hence the enthalpy change for the reaction. (ii) State two assumptions that have been made in order to calculate the answer above from the data given.
CuSO4(aq) + Zn(s) → Cu(s) + ZnSO4(aq) She placed 50 cm3 of 0.140 mol dm-3 copper
sulfate solution in a polystyrene cup and recorded the temperature for two minutes before adding an excess of zinc powder. She continued stirring and taking the temperature for a further fifteen minutes to produce the graph on the right.
(i) Determine the temperature increase if there had been no heat lost to the surroundings and hence the enthalpy change for the reaction. (ii) State two assumptions that have been made in order to calculate the answer above from the data given.
Physical Chemistry
Write the chemical equation and mechanism of pinacol-pinacolone
rearrangement.
rearrangement.
Physical Chemistry
For the following reaction, which of the following is a conjugate acid-base pair?
HC₂O₄⁻(aq) + H₂O(l) → H₃O⁺(aq) + C₂O₄²⁻(aq)
HC₂O₄⁻ and H₂O
HC₂O₄⁻and H₃O⁺
H₂O and C₂O₄²⁻
HC₂O₄⁻ and C₂O₄²⁻
HC₂O₄⁻(aq) + H₂O(l) → H₃O⁺(aq) + C₂O₄²⁻(aq)
HC₂O₄⁻ and H₂O
HC₂O₄⁻and H₃O⁺
H₂O and C₂O₄²⁻
HC₂O₄⁻ and C₂O₄²⁻
Physical Chemistry
A flask contain 1.00 mol of He(g) at 273K and 1 atm. How many molecules in the sample have speeds in the range of 90.000 to 90.002 m/s ?
Physical Chemistry
Calculate the percentage change in the equilibrium constant Kx of the reaction
H2CO(g) CO(g)+H2(g) when the total pressure increased from 1 bar to 2 bar at constant pressure.
H2CO(g) CO(g)+H2(g) when the total pressure increased from 1 bar to 2 bar at constant pressure.
Physical Chemistry
We have a gas mixture and the total pressure of this mixture is 2 atm. Find the mole fractions and partial pressures of each component according to the data below.
[ ] N2 > % 75,52
O2 > % 22,95
Ar > % 1,28
CO2 > % 0,25
———————-
A clean, dried and vacuumed glass tube weighs 40.1305g. When this tube is filled with water at 240C, it comes to 138.2410 g. When filled with propylene gas, 40,2959 g comes at 240C and under 740.3 mmHg pressure conditions. What is the mole mass of propylene gas?
[ ] N2 > % 75,52
O2 > % 22,95
Ar > % 1,28
CO2 > % 0,25
———————-
A clean, dried and vacuumed glass tube weighs 40.1305g. When this tube is filled with water at 240C, it comes to 138.2410 g. When filled with propylene gas, 40,2959 g comes at 240C and under 740.3 mmHg pressure conditions. What is the mole mass of propylene gas?
