Question

A welder using a tank of volume 7.50×10⁻² m3 fills it with oxygen (with a molar mass of 32.0 g/mol ) at a gauge pressure of 3.30×10⁵ Pa and temperature of 36.6 ∘C. The tank has a small leak, and in time some of the oxygen leaks out. On a day when the temperature is 21.6 ∘C, the gauge pressure of the oxygen in the tank is 1.95×10⁵ Pa .

A) Find the initial mass of oxygen. kg

B) Find the initial mass of oxygen. kg

Answer 1

Solution:-

Given –

Volume of tank – 7.50*10^-2 m³

Gauge pressure – 3.30*10⁵ pa

Temp – 36.6⁰

Molar mass – 32.0 g/mol

A)     Calculate Initial mass of oxygen

Initial mass of o2 = PV/RT

3.30*10⁵ pa * 7.50*10^-2 m³ / 8.314472 m³pak^-1mol^-1(273+36.6)

= 24750 / 2574.16053

= 9.6147 moles of oxygen or

9.6147 * 32. 0 g/mol

= 307.67 g of oxygen

= 0.30767 kg of oxygen

Initial mass of oxygen = 0.30767 kg

B)     Calculate Initial mass of oxygen

Initial mass of o2 = PV/RT

3.30*10⁵ pa * 7.50*10^-2 m³ / 8.314472 m³pak^-1mol^-1(273+36.6)

= 24750 / 2574.16053

= 9.6147 moles of oxygen or

9.6147 * 32. 0 g/mol

= 307.67 g of oxygen

= 0.30767 kg of oxygen

Initial mass of oxygen = 0.30767 kg