2. what volume of oxygen is produced at stp when 6.58 x 1024 molecules of water is
decomposed according to the following reaction?

2 h2o → 2 h2 + o2

V = 122.2 L

Explanation:

Given data:

Number of molecules of water = 6.58×10²⁴

Volume of oxygen produced = ?

Solution:

Chemical equation:

2H₂O → 2H₂ + O₂

Number of moles of water:

Number of moles = 6.58×10²⁴/ 6.022 ×10²³

Number of moles =  1.09 ×10¹ mol

Number of moles =  10.9 mol

Now we will compare the moles of water with oxygen:

                        H₂O         :         O₂

                         2             :          1

                         10.9        :           1/2×10.9 = 5.45 mol

Volume of oxygen:

PV = nRT

V = nRT/P

V = 5.45 mol × 0.0821 L. atm. K⁻¹. mol⁻¹× 273 k / 1 atm

V = 122.2 L. atm. / 1 atm

V = 122.2 L