Asample of gas in a cylinder as in the example in part a has an initial volume of 52.0 l , and you have determined that it contains 1.40 moles of gas. the next day you notice that some of the gas has leaked out. the pressure and temperature remain the same, but the volume has changed to 13.0 l . how many moles of gas (n2) remain in the cylinder?

0.35 moles

Explanation:

Avogadro's Law: This law states that volume is directly proportional to the number of moles of the gas at constant pressure and temperature.

  (At constant temperature and pressure)  

where,

= initial volume of gas = 52.0 L

= final volume of gas = 13.0 L

= initial number of moles = 1.40

= final number of moles = ?

Now put all the given values in the above equation, we get the final pressure of gas.

Therefore, the moles of the gas that will remain is 0.35 moles.

in the given question, the partial pressure is calculated by using the ideal gas equation, that is, pv = nrt

here, p is pressure, v is volume = 25 l, n is number of moles = 0.0104 moles, r is gas constant = -0.0821 l.atm / mol.k

t is temperature = 273 k

p = nrt / v

p = (0.0104 mol × 0.0821 l.atm / mol.k × 273 k) / 25 l

= 0.0093 atm