Question

How do I use bridge notation to solve this problem? How many grams of HgO must react to produce 3.75 mol O2?

Answer 1

Answer: Given the equation: 2HgO(s) → 2Hg(l) +1O2(g)
From the equation we can see that from 2 mol. of HgO we get 1 mol. of O2. That’s why if we need 3,75 mol O2 we must take two times more HgO 7,5 mol.
From Mendeleev periodic table we know that the molar mass of orange mercury(II) oxide is 216.59 grams per one mole (g/mol.) In our case we need to get 7,5 mol, so the mass of HgO would be m=7,5 mol x 216.59 g/mol = 1624.425 g. Our answer is 1624.425 g of HgO.