Question

Part A

What is the average reaction rate between 0. and 1500. s ?

Express your answer to three significant figures and include the appropriate units

Part B

What is the average reaction rate between 500. and 1200. s ?

Express your answer to three significant figures and include the appropriate units.

Part C

What is the instantaneous rate of the reaction at t=800. s ?

Express your answer to two significant figures and include the appropriate units

Average and Instantaneous Reaction Rates

An average reaction rate is calculated as the change in the concentration of reactants or products over a period of time in the course of the reaction. An instantaneous reaction rate is the rate at a particular moment in the reaction and is usually determined graphically.

The reaction of compound A forming compound B was studied and the following data were collected:

Time (s )	[A] (M )
0.	0.184
200.	0.129
500.	0.069
800.	0.031
1200.	0.019
1500.	0.016

Answer 1

Average rate of reaction is defined as the change in concentration of reactant or product in given time interval t.

Rav= (change in concentration / time interval)

= (0.016 - 0.184)/(1500-0) = (-0.000112) Mol /LS

Average rate = -0.112×10^-3 Mol/LS

Negative sign indicates that decrease in concentration of reactant A with time t.

(B) average rate of reaction

Rav= (0.019-0.069)/(1200-500)

= (-7.142×10^-5 )Mol/LS

Negative sign indicate that concentration of reactant is decreasing.

(C)

Instantaneous rate of reaction = (concentration of A/ instantaneous time)

= (0.031/800)= 3.87× 10^-5 Mol/LS