Study the scenario and the balanced equation.

While a Bunsen burner is ignited, 7.45 x 1024 mol of methane (CH4) reacts with an excess of oxygen (O2).

CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)
(M H2O = 18.0 g/mol; M CH4 = 16.0 g/mol)

What is the theoretical yield of water produced?

A) 2.68 × 1026 mol H2O
B) 4.14 × 1023 g H2O
C) 4.14 × 1023 mol H2O
D) 2.68 × 1026 g H2O

                      Option-D (2.68 × 10²⁶ g of H₂O)

Explanation:

                      The balance chemical equation for the combustion of Methane is as follow;

                                    CH₄ + 2 O₂ → CO₂ + 2 H₂O

According to balanced equation,

                         1 mole of CH₄ produced  =  2 moles of H₂O

So,

              7.45 × 10²⁴ moles of CH₄ will produce  = X moles of H₂O

Solving for X,

                      X =  7.45 × 10²⁴ mol × 2 mol / 1 mol

                      X =  1.49 × 10²⁵ mol of H₂O

As there is no option containing calculated moles of H₂O produced so, we will convert the moles of H₂O to mass and then look for that answer in given choices.

As,

                     Mass  =  Moles × M.Mass

                     Mass  =  1.49 × 10²⁵ mol × 18.01 g/mol

                    Mass =  2.68 × 10²⁶ g of H₂O

Okay! That's Option-D.