Question

What mass of water, in grams, would have to be decomposed

toproduce 15.1 L of molecular oxygen at STP?

Answer 1

24.3 g

Step-by-step explanation:

Let's consider the decomposition of water.

H₂O → H₂ + 0.5 O₂

We can establish the following relations.

• At STP, 1 mole of a gas occupies a volume of 22.4 L.

• The molar ratio of H₂O to O₂ is 1:0.5.
• The molar mass of H₂O is 18.02 g/mol.

The mass of water required to produce 15.1 L of O₂ is:

`15.1 LO_(2)(1molO_(2))/(22.4LO_(2)) .(1molH_(2)O)/(0.5molO_(2)) .(18.02gH_(2)O)/(1molH_(2)O) =24.3gH_(2)O`