Hydrogen Peroxide Decomposes into Water and Oxygen in a First-Order

Multiple Choice

Hydrogen peroxide decomposes into water and oxygen in a first-order process. H₂O₂(aq) → H₂O(l) + 1/2 O₂(g)
At 20.0°C,the half-life for the reaction is 3.92 × 10⁴ seconds.If the initial concentration of hydrogen peroxide is 0.52 M,what is the concentration after 7.00 days?

A) 1.2 × 10-⁵ M
B) 0.034 M
C) 0.074 M
D) 0.22 M
E) 0.52 M