[Rutherford]

In the reaction:
A+2B 2C
the starting concentration of substances A and B are 0.3mol/dm³ and 0.5mol/dm³. The speed constant of the reaction is 0.4dm⁶/mol²s. Calculate Δ [C]/Δt:
a)at the beginning of the reaction
b)after some time, when the concentration of substance A reduces by 0.1mol/dm³.

The problem is that I don't have the answer so I need someone to check my thoughts:
a)V=k[A][ B]²=Δ [C]/Δt*1/2
Δ [C]/Δt=0.06mol/dm³s
b)Same equation. but the concentrations of A and B are 0.2mol/dm³ and 0.3mol/dm³
Δ [C]/Δt=0.0072mol/dm³s
Correct?

[Rutherford]

V=k[A][ B]²= Δ [C]/Δt*1/2
this is the formula, didn't know why it isn't shown.

[Rutherford]

Why the formula isn't shown properly?

[Borek]

Strange, apparently [itex]\Delta[C[/itex] is not rendered correctly. I will try to check why.

Please remember you can format such equations using LaTeX, it will give much better results.

Δ[C

[juanrga]

In the reaction:
A+2B 2C
the starting concentration of substances A and B are 0.3mol/dm³ and 0.5mol/dm³. The speed constant of the reaction is 0.4dm⁶/mol²s. Calculate Δ [C]/Δt:
a)at the beginning of the reaction
b)after some time, when the concentration of substance A reduces by 0.1mol/dm³.

The problem is that I don't have the answer so I need someone to check my thoughts:
a)V=k[A][ B]²=Δ [C]/Δt*1/2
Δ [C]/Δt=0.06mol/dm³s
b)Same equation. but the concentrations of A and B are 0.2mol/dm³ and 0.3mol/dm³
Δ [C]/Δt=0.0072mol/dm³s
Correct?

V=k[A][ B]²= 1/2 d[C]/dt

If you assume d[C]/dt  = Δ [C]/Δt you are basically assuming that the formation rate of C is a constant, which cannot be true because the concentrations of A and B vary with time.

[Rutherford]

The reaction goes into one direction all the time, so I thought I can use that formula. How to solve this problem then?