You are given 3.0 grams of solid sodium to react to pure water which has a molarity of 55.6 M. How many milligrams of H2 can be produced if you react 6 mL of the water with 3.0 grams of solid sodium. Na (s) + H2O > NaOH (aq) + H2 (g)

= 15.51 mL

Explanation:

Here's is the reaction:

2HgO(s) ⇒ 2 Hg(s)+O₂(g)

In this reaction 2mol HgO =  1mol O₂

The molecular weight of HgO = 216.59g

so, 3.0g HgO = 3.0g x 1.00molHgO/216.59gHgO

= 0.0138511 molHgO

The amount of Oxygen follows:

0.0138511 molHgOx1/2= 0.00692555 mol O₂

Now, volume of 1 any gas = 22400mL

so, 0.00692555 mol O₂ x22400mLO₂/1mol O₂

= 15.513232mL O₂