Question

if 120 ml of oxygen is collected over water at 27 degrees celsius & 740 mm pressure what will the volume of the dry gas be at STP

Answer 1

Answer:

                       V₂ = 106.33 ml

Explanation:

Data Given:

                 Initial Temperature  =  T₁  =  27 °C + 273.15 = 300.15 K

                 Initial Pressure  =  P₁  =  740 mmHg

                 Initial Volume  =  V₁  =  120 ml

                 Final Temperature  =  T₂  =  0 °C + 273.15 = 273.15 K

                 Final Pressure  =  P₂  =  760 mmHg

                 Fnal Volume  =  V₂  =  ?

Formula Used:

Let's assume that the Oxygen gas is acting as an Ideal gas, the according to Ideal Gas Equation,

                       P₁ V₁ / T₁  =  P₂ V₂ / T₂

Solving for V₂,

                       V₂ = P₁ V₁ T₂/ T₁ P₂

Putting values,

                       V₂ = 740 mmHg × 120 ml × 273.15 K / 300.15 K × 760 mmHg

                       V₂ = 106.33 ml