Determine the concentration of hydrogen molecules at a pressure of 100п if the average value of the speed of thermal

| May 10, 2021 | education

Determine the concentration of hydrogen molecules at a pressure of 100п if the average value of the speed of thermal movement of molecules is 450m / s.

P = 100 Pa.

M (H2) = 2 * 10 ^ -3 kg / mol.

Vav = 450 m / s.

Na = 6 * 10 ^ 23 mol ^ -1.

n -?

According to the basic equation of molecular kinetic theory, the gas pressure P is determined by the formula: P = n * m0 * Vav ^ 2/3, where n is the concentration of molecules, m0 is the mass of one molecule, Vav is the average speed of the thermal motion of molecules.

We find the mass of one molecule by the formula: m0 = M (H2) / Na, where M (H2) is the molar mass of hydrogen, Na is Avogadro’s number.

P = n * M (H2) * Vav ^ 2/3 * Na.

n = P * 3 * Na / M (H2) * Vav ^ 2.

n = 100 Pa * 3 * 6 * 10 ^ 23 mol ^ -1 / 2 * 10 ^ -3 kg / mol * (450 m / s) ^ 2 = 4.4 * 10 ^ 23 m ^ 3.

Answer: the concentration of molecules is n = 4.4 * 10 ^ 23 m ^ 3.



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