Question

4. A sample of nitrogen at 20 degrees Celsius was compressed to 300ml to

0.360mL and its new pressure was found to be 400 Pa. What was the
initial pressure in kPa?

Answer 1

We are given:

V(i) = 0.3 L V(f) = 0.36 L

P(i) = x pa P(f) = 400 pa

T(i) = T(f) = 293 k

Using the gas formula:

PV = nRT

Since n , R and T are constant,

PV = k (where k is a constant)

Hence we can say that:

P(i) * V(i) = P(f) * V(f)

x * 0.3 = 0.36 * 400

x = 14.4/0.3

x = 480 pascals

Hence the initial pressure is 480 pascals

Converting to Kpa, we have to divide by 1000

Initial pressure (Kpa) = 0.48