Chapter 11, Problem 23QRT

(a)

Interpretation Introduction

Interpretation:

Initial rate of the reaction for the given concentrations of  $Pt{(N{H}_3)}_{2}C{l}_2$ has to be calculated.

Concept Introduction:

The relationship between rate and initial concentration of reactant is described by rate law.  It is an experimentally determined equation and cannot be found out theoretically from the stoichiometry of the reactants and products.

  $rate=k{\left[concentrationofthereac\tan t\right]}^m$

Where, $k$ is the rate constant and $m$ is the order of the reaction.

(b)

Interpretation Introduction

Interpretation:

The change in the rate of disappearance of $Pt{(N{H}_3)}_{2}C{l}_2$ with its initial concentration has to be determined.

Concept Introduction:

Refer to part (a).

(c)

Interpretation Introduction

Interpretation:

The relation between rate law and the concentration of $Pt{(N{H}_3)}_{2}C{l}_2$ has to be explained.

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Concept Introduction:

(d)

Interpretation Introduction

Interpretation:

The effect of initial concentration of $Pt{(N{H}_3)}_{2}C{l}_2$ on the rate of disappearance of $C{l}^{-}$ has to be explained.

Concept Introduction:

Consider the following reaction.

  $aA+bB\to cC$

Where $A$ and $B$ are reactants and $C$ is the product. a, b and c are stoichiometric co-efficient of A, B and C.

  $rate=-\frac{1}{a}\frac{\Delta \left[A\right]}{\Delta t}=-\frac{1}{b}\frac{\Delta \left[B\right]}{\Delta t}=\frac{1}{c}\frac{\Delta \left[C\right]}{\Delta t}$

Where,

    $-\frac{\Delta \left[A\right]}{\Delta t}=$ rate of disappearance of A

    $-\frac{\Delta \left[B\right]}{\Delta t}=$ rate of disappearance of B

    $\frac{\Delta \left[C\right]}{\Delta t}=$ rate of appearance of C

Rate of the reaction can be expressed in terms of change in concentration of reactant and products by multiplying the reciprocal of the corresponding stoichiometric co-efficient to that.

When the rate is expressed in terms of change in reactant concentration, a minus sign has to be given.  Since change in time will be a positive quantity and reactant concentration decreases with time change in concentration of reactant will be negative.  So in order to make the rate a positive quantity negative sign is given.