Question

People buying food in sealed bags at high elevations often notice that the bags are puffed up because the air inside has expanded. A bag of pretzels was packed at a pressure of 1.01 atm and a temperature of 21.0°C. When opened at a summer picnic in Santa Fe, New Mexico, at a temperature of 31.0°C, the volume of the air in the bag is 1.40 times its original volume. What is the pressure of the air (in atm)?

Answer 1

The pressure in Santa Fe, New Mexico is 0.746atm

Step-by-step explanation:

You can solve this question using combined gas law:

P₁V₁ / T₁ = P₂V₂ / T₂

Where P is pressure,

V is volume,

and T is absolute temperature in K for 1, initial state and, final states.

The initial conditions are:

P₁ = 1.01atm

V₁ = 1

T₁ = 21.0°C + 273.15K = 294.15K

And final conditions are:

P₂ = Our unknown

V₂ = 1.4

T₂ = 31.0°C + 273.15K = 304.15K

Replacing:

P₁V₁ / T₁ = P₂V₂ / T₂

1.01atm*1 / 294.15K = P₂*1.4 / 304.15K

P₂ = 0.746atm

The pressure in Santa Fe, New Mexico is 0.746atm