When mercury(ii) oxide gas. how many molecules of oxygen gas are produced if 6.54g of mercury(ll) oxide are heated?

0.09 ×  10²³ molecules of  O₂

Explanation:

Given data:

Mass of mercury(II) oxide = 6.54 g

Molecules of oxygen produced = ?

Solution:

Chemical equation:

2HgO → 2Hg + O₂

Number of moles of HgO:

Number of moles = mass/ molar mass

Number of moles = 6.54 g / 216.6 g/mol

Number of moles = 0.03 mol

Now we will compare the moles of HgO with oxygen.

                       HgO         :           O₂

                         2             :            1

                     0.03            :          1/2×0.03 = 0.015 mol

Number of molecules of oxygen:

1 mole of O₂  = 6.022 × 10²³ molecules of O₂  

0.015  mole of O₂ :

0.015  × 6.022 × 10²³ molecules of  O₂

0.09 ×  10²³ molecules of  O₂

answer:

technetium is the most reactive. this is followed by silver. the least reactive out of these three elements is strontium.