Methane and oxygen react to form carbon dioxide and water.What mass of water is formed if 6.4 g of methane reacts with 25.6 g of oxygen to produce 17.6 g of carbon dioxide?
A)14.4 g
B)17.6 g
C)29.6 g
D)32.0 g

Question

Quizplus · Accepted Answer

The balanced chemical equation for the reaction is:
CH4 + 2O2 → CO2 + 2H2O

Using the given masses we can calculate the limiting reagent:
Moles of methane = 6.4 g / 16.04 g/mol = 0.4 mol
Moles of oxygen = 25.6 g / 32.00 g/mol = 0.8 mol

From the balanced equation, 1 mole of methane reacts with 2 moles of oxygen to produce 2 moles of water.
So, 0.4 mol of methane reacts with 0.8 mol of oxygen to produce 0.8 mol of water.

Moles of water = 0.8 mol
Mass of water = moles of water × molar mass of water
= 0.8 mol × 18.02 g/mol
= 14.416 g ≈ 14.4 g

Therefore, the mass of water formed is 14.4 g. Hence the correct choice is A.

Methane and Oxygen React to Form Carbon Dioxide and Water