Question

Mercury(II) oxide (HgO) decomposes to form mercury (Hg) and oxygen (O2). The balanced chemical equation is shown below.

2HgO ----> 2Hg + O2

The molar mass of HgO is 216.59 g/mol. The molar mass of O2 is 32.00 g/mol. How many moles of HgO are needed to produce 250.0 g of O2?

Answer 1

To answer this item, we determine first the number of moles of O2 produced.
                      n = (250 g O2) / (32 g O2/mol) = 7.8125 moles O2
From the given balanced chemical equation, every one mole of O2 needs 2 moles mercury oxide. 
                     n HgO = (7.8125 moles O2) x (2 moles HgO / 1 mole O2)
                     n HgO = 15.625 moles O2

Answer 2

Answer:

C) 15.63

Explanation: