Answer:

Explanation:
1. Calculate the moles of copper(II) hydroxide

2. Calculate the molecules of copper(II) hydroxide
A chemical reaction does happen between sodium and water to form Sodium Hydroxide (NaOH) and Hydrogen Gas (H-2)
Answer:
HgO (empirical formula)
Explanation:
4.08 - 3.78 = 0.3g (oxygen)

0.02 : 0.02
0.02/0.02 : 0.02/0.02
1 : 1 (ratio)
HgO ( empirical formula)
2HgO ----> 2Hg + O2 ( your equation correct)