[KneelsBoar]

Hey, I'm struggling a bit with this question.

For a simple chemical reaction:

3A + B → C + 2D

The rate of the reaction is given by -Δ[A]/Δt.

Which of the rate equations below is equal to -Δ[A]/Δt

Select one:
a. 3Δ[D]/2Δt
b. -3Δ[D]/2Δt
c. -2Δ[D]/3Δt
d. 2Δ[D]/3Δt

I know that in a system with more than one reactant, rate of reaction can be related by:

-1/a x Δ[A]/ΔT = -1/b x Δ[ B]/ΔT = 1/c x Δ[C]/ΔT = 1/d x Δ[D]/ΔT

But I'm not sure how to apply this rule or what it really means

Thanks.

[Borek]

It is just about stoichiometry. If for every single mole of consumed B one mole of C is produced, [tex]\frac {dB}{dt} = -\frac {dC}{dT}[/tex] Just apply this line of thinking to other substances, remembering their stoichiometric coefficients.