If the gram of 2HgO is 12.how grams of oxygen in 2HgO---------2Hg +O2

To find out the grams of oxygen in 2HgO, you need to first find the molecular weight of HgO and then calculate the mass of oxygen in 2HgO.

The molecular weight of HgO is:
Hg (Mercury) = 200.59 g/mol
O (Oxygen) = 16 g/mol
HgO = 200.59 g/mol + 16 g/mol = 216.59 g/mol

Now we need to find the percentage of oxygen in HgO:
Percentage of oxygen = (mass of oxygen / mass of HgO) x 100
Percentage of oxygen = (16g / 216.59g) x 100 = 7.39 %

Next, we can find the weight of oxygen in 2HgO:
Mass of Oxygen = (12g of 2HgO) x (7.39 %)
Mass of Oxygen = 12g x 0.0739 = 0.8868 g

Therefore, the grams of oxygen in 2HgO is 0.8868g.