Answer:
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