Question

For the hypothetical reaction A+3B2C, the rate of appearance of C given by

A) (Δ[C]/Δt = -Δ[A]/Δt
B) (Δ[C]/Δt = -(3/2)Δ[B]/Δt
C) (Δ[C]/Δt = -(2/3)Δ[B]/Δt
D) (Δ[C]/Δt = -(1/2)Δ[A]/Δt

Answer 1

Δ[C]/Δt = (-2/3)*Δ[B]/Δt

thus the answer C is correct

Step-by-step explanation:

Assuming that the reaction is

A+3B→2C

then denoting C as the concentrations and ν as the stoichiometric coefficients

(Ca-Ca₀)/νa = (Cb-Cb₀)/νb = (Cc-Cc₀)/νc

differenciating with respect to t

(dCa/dt)/νa = (dCb/dt)/νb = (dCc/dt)/νc

then

dCc/dt = (νc/νa)*(dCa/dt)

dCc/dt = (νb/νa)*(dCb/dt)

since νa=1 , νb=3 , νc=(-2) , doing Δ[C]/Δt= dCc/dt and for the other components

Δ[C]/Δt = (-2)*Δ[A]/Δt

Δ[C]/Δt = (-2/3)*Δ[B]/Δt

thus the answer C is correct