Answer:
Mass of zinc react with oxygen = 156.91 g
Explanation:
Given data:
Volume of oxygen = 18.9 L
Temperature = 15°C
Pressure = 1.50 atm
Mass of zinc react with oxygen = ?
Solution:
Chemical equation:
2Zn + O₂   →    2ZnO
Number of moles of oxygen:
PV = nRT
1.50atm ×18.9 L = n× 0.0821 atm.L / mol.K × 288 K
28.35 atm.L =  n× 23.64atm.L / mol
n = 28.35 atm.L Â / 23.64atm.L / mol
n = 1.2 mol
Now we will compare the moles of oxygen and Zn.
       O₂      :      Zn
        1       :       2
       1.2      :     2/1×1.2 = 2.4 mol
Mass of zinc required:
Mass = number of moles × molar mass
Mass = 2.4 mol × 65.38 g/mol
Mass = 156.91 g