Question

Hydrogen decomposes quickly when exposed to light. The reaction for decomposing hydrogen peroxide is: 2H2O2 → 2H2O + O2. If 45.55 g of H2O2 decomposes, what is the mass of H2O in the reaction above?

a) 15.18 g
b) 20.24 g
c) 25.30 g
d) 30.36 g

Answer 1

The mass of water (H2O) produced when 45.55 g of hydrogen peroxide (H2O2) decomposes is approximately 24.15 g, which is closest to option C) 25.30 g. There seems to be a discrepancy, as this value does not exactly match any of the given options.

Step-by-step explanation:

To determine the mass of water (H2O) produced when 45.55 g of hydrogen peroxide (H2O2) decomposes based on the reaction equation 2H2O2 → 2H2O + O2, we first need to calculate the molar mass of H2O2 (34.01 g/mol) and H2O (18.02 g/mol). Then, we can find the moles of H2O2 that decomposed by dividing 45.55 g by its molar mass.

Moles of H2O2 = 45.55 g / 34.01 g/mol = 1.34 moles

According to the balanced chemical equation, 2 moles of H2O are produced for every 2 moles of H2O2 that decompose, meaning the molar ratio is 1:1.

Moles of H2O produced = 1.34 moles

Now, we can calculate the mass of H2O formed by multiplying the moles of H2O by its molar mass:

Mass of H2O = 1.34 moles × 18.02 g/mol = 24.15 g

Therefore, the mass of water (H2O) produced in the reaction is approximately 24.15 g, which is closest to answer option C) 25.30 g. This value is not an exact match to any of the given options, suggesting a possibility of a typo or an error in the options provided.