A Gas-Phase Decomposition Is First-Order with Respect to the Reactant

question 42

Multiple Choice

A gas-phase decomposition is first-order with respect to the reactant, R. If the initial concentration of R is 1.0 × 10⁻⁴ mol L⁻¹and the rate constant k = 1.08 × 10⁻⁶ s⁻¹, what concentration of R remains after 25 days?

• A)1.0 × 10 ⁻³ mol L ⁻¹
• B)1.0 × 10 ⁻⁴ mol L ⁻¹
• C)9.6 × 10 ⁻⁵ mol L ⁻¹
• D)4.3 × 10 ⁻⁵ mol L ⁻¹
• E)9.7 × 10 ⁻⁶ mol L ⁻¹

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Definitions:

Meninges

The three layers of protective tissue (dura mater, arachnoid mater, and pia mater) covering the brain and spinal cord.

Arachnoid

A delicate membrane that encloses the brain and spinal cord, situated between the dura mater and pia mater.

Pia

Short for pia mater, it is the delicate innermost membrane enveloping the brain and spinal cord.