What mass of magnesium will react with a 0.25 L container of oxygen gas at 80oC and 770 mmHg?

Question

.209 g

.945 g

.418 g

.124 g

Answer 1

T = 80 + 273 = 353 K

p = 770 / 760 =1.01 atm

n = pV / RT = 1.01 x 0.25 / 0.0821 x 353 = 0.00871 ( moles O2)

2 Mg + O2 >> 2 MgO

moles Mg = 2 x 0.00871 =0.0174

Mass Mg = 0.0174 mol x 24 g/mol = 0.418 g