How many moles of oxygen are required to completely react with 16.1 grams of magnesium metal according to the equation: 2 Mg(s) + O2(g) → 2 MgO(s) ?

1 Answer
Mar 14, 2016

Answer:

#0.33# moles of #O_2#

Explanation:

  1. Locate #Mg# in the periodic table and take note of the atomic mass;
  2. Find the number of moles of magnesium by dividing the mass as provided in the problem against the atomic mass of magnesium;
    #n Mg=(mass)/(at. mass)#
    #n Mg=0.67 mol#
  3. Then, compute the number of moles of #O_2# needed to completely react with magnesium through conversion method;
    #0.67 cancel(mol Mg) #x# (1 mol O_2)/(2 cancel(mol Mg))#
  4. Make sure to cancel out units that are not needed leaving only the desired units;
  5. The final answer is found to be #0.33# moles of #O_2#