Question

The gas-phase reaction of NO with F2 to form NOF and F has an activation energy of Ea = 6.30 kJ/mol and a frequency factor of A = 6.00×108M−1⋅s−1 . The reaction is believed to be bimolecular:NO(g)+F2(g)→NOF(g)+F(g)What is the rate constant at 695 ∘C ?Express your answer to three significant digits with the appropriate units. For compound units, place a multiplication dot between units (e.g. J⋅mol−1⋅K−1).(I got 2.74*10^8 M-1s-1 but it is wrong. I got a message saying "Enter your answer using dimensions of rate constant units for second-order reaction". Can someone please help me?)

Answer 1

Answer:

2.74 × 10⁸ M⁻¹.s⁻¹ = 2.74 × 10⁸ L.mol⁻¹.s⁻¹

Explanation:

Let's consider the following second-order reaction.

NO(g) + F₂(g) → NOF(g) + F(g)

We can find the rate constant (k) using the Arrhenius equation.

$k=A \times e^{-Ea/R\times T}$

where,

• A: frequency factor

• Ea: activation energy

• R: ideal gas constant

• T: absolute temperature (695°C + 273.15 = 968 K)

$k=6.00 \times 10^{8} M^{-1}.s^{-1} \times e^{-6.30\times 10^{3}J /(8.314 J/mol.K)\times 968 K} = 2.74 \times 10^{8} M^{-1}.s^{-1}$