In the first 22.0 s of this reaction, the concentration of HBr dropped from 0.590 M to 0.465 M . Calculate the average rate of the reaction in this time interval.

The average rate is 2.84 X 10⁻³ Ms⁻¹

Explanation:

Average rate = -0.5*Δ[HBr]/Δt

given;

[HBr]₁ = 0.590 M

[HBr]₂ = 0.465 M

Δ[HBr] = [HBr]₂  - [HBr]₁ = 0.465 M - 0.590 M = -0.125 M

Δt Change in time = 22.0 s

Average rate = -0.5*Δ[HBr]/Δt

Average rate = - 0.5(-0.125)/22

Average rate = 0.00284 Ms⁻¹ = 2.84 X 10⁻³ Ms⁻¹

Therefore, the average rate is 2.84 X 10⁻³ Ms⁻¹

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)