Question

1 Still for the reaction: 3BrO-(aq) --> BrO3-(aq) + 2Br-(aq), what is the rate of reaction in M/s, if Δ[BrO- ]/Δt = -0.020 M/s?

2 Under a different set of conditions Δ[BrO3- ]/Δt = 0.019 M/s. What is the rate of reaction in M/s?

3 Under a different set of conditions Δ[Br- ]/Δt = 0.016 M/s. What is the rate of reaction in M/s?

4 If Δ[BrO3- ]/Δt = 0.021 M/s. What is Δ[Br- ]/Δt in M/s? Reminder, the rate of change [BrO3- ] is Δ[BrO3- ]/Δt (work please)

Answer 1

Given reaction is :

3BrO-(aq) --> BrO3-(aq) + 2Br-(aq)

Delta [BrO-] / Delta t = - 0.020 M/s

Since there are 3 moles of BrO- reacts so we need to divide the given rate by 3

Rate of reaction =-1/3 Delta [BrO-] / Delta t

Negative sign is used since concentrations of reactants are decreasing.

Rate of reaction = - ( - 0.020 /3 ) M /s

= 0.06667 M /s

2). In second question the rate of formation of BrO3^- is given.

In this case rate is = Delta BrO3^- / Delta t

Rate of reaction = 0.019 M/s        ( here we did not use negative sign since the BrO3^- is the product and its concentration is increasing.

3)

Rate = 1 /2 ( 0.016 ) M/s   = 0.008 M/s      ( coefficient of Br- = 2 )

4)

In this part of the problem we show the relation rate of products

Delta [BrO3-] / delta t = Delta [Br-] / 2 delta t

0.021 M/s x 2 = Delta [Br-] / delta t

Delta [Br-] / delta t = 0.042 M/s