How many grams of zinc do you need to make 56 g of zinc oxide?

Solution:

Let’s compose the equation for the reaction of interaction of zinc with oxygen:
2Zn + O2 = 2ZnO;

Let’s find the molecular weight of zinc oxide:
65 + 16 = 81 g / mol;

Let’s find the amount of substance in zinc oxide:
56/81 = 0.691 mol;

Zinc has the same coefficient as before zinc oxide. This means that the amount of substance in zinc is 0.691 mol. Let’s find the mass of zinc:
0.691 * 65 = 44.915 grams;

Answer: You need 44.915 grams of zinc.