Question

CH4 + 202 → CO2 + 2H2O
How many grams of O2 needed to produce 36 grams of H2O?

Answer 1

Mass = 64 g

Step-by-step explanation:

Given data:

Mass of water produced = 36 g

Mass of oxygen needed = ?

Solution:

Chemical equation:

CH₄ + 2O₂ CO₂ + 2H₂O

Number of moles of water produced:

Number of moles = mass/molar mass

Number of moles = 36 g/ 18 g/mol

Number of moles = 2 mol

Now we will compare the moles of water and oxygen.

H₂O : O₂

2 : 2

Mass of oxygen:

Mass = number of moles × molar mass

Mass = 2 mol × 32 g/mol

Mass = 64 g