Calculate the average kinetic energy of 1 mol of hydrogen molecules and of 1 mol of sulfur hexafluoride molecules at 25 degrees Celsius.
To calculate the average kinetic energy of a gas, we can use the formula:
KEavg = (3/2) * k * T
where KEavg is the average kinetic energy, k is the Boltzmann constant, and T is the temperature in Kelvin.
First, let's convert the Celsius temperature to Kelvin:
T = 25 + 273.15
T ≈ 298.15 K
Now, we need to find the molar mass of hydrogen (H2) and sulfur hexafluoride (SF6) to calculate the number of moles. The molar mass of an element is the sum of the atomic masses of its constituents.
The atomic mass of hydrogen (H) is 1 g/mol, so the molar mass of hydrogen gas (H2) is 2 g/mol.
For sulfur hexafluoride (SF6), the atomic mass of sulfur (S) is 32.06 g/mol, and the atomic mass of fluorine (F) is 18.998 g/mol. Since there are six fluorine atoms in sulfur hexafluoride, we multiply the atomic mass of fluorine by 6 and add the atomic mass of sulfur:
Molar mass of SF6 = (6 * 18.998 g/mol) + 32.06 g/mol
Molar mass of SF6 ≈ 146.06 g/mol
Now that we have the molar mass, we know that 1 mole of any substance contains Avogadro's number (approximately 6.022 x 10^23) of particles.
Let's calculate the average kinetic energy for 1 mole of hydrogen (H2) molecules:
KEavg (H2) = (3/2) * k * T
KEavg (H2) = (3/2) * 1.380649 x 10^-23 J/K * 298.15 K
Next, let's calculate the average kinetic energy for 1 mole of sulfur hexafluoride (SF6) molecules:
KEavg (SF6) = (3/2) * k * T
KEavg (SF6) = (3/2) * 1.380649 x 10^-23 J/K * 298.15 K
By plugging the values into the formulas, you can calculate the average kinetic energy for both hydrogen and sulfur hexafluoride molecules.