Question

An electrical vacuum tube was sealed off during manufacturing at a pressure of 1.2 *10^7 mmhg at 27degree Celsius and volume of 100cm what is the pressure of the tube and how mana gas of molecule remain in the tube

Answer 1

3.86×10^11 molecules of gas remain in the tube

P = nkT

n = P/kT

= hdg/kT

Number of molecules in the electron tube is = n×V = hdgV/kT

⟹n = hdg/kT

=

1.2×10^−10 ×13600 × 9.8 × 100 × 10^−6/1.38×10^−23 × 300

= 3.86×10^11