Question

Match the plots given in List I with their slopes given in List II and select the correct answer using the code given below the lists :

List I	List II
P. c $\upsilon s$ t (abscissa) for zero order reaction	1.Unity
Q. log c $\upsilon s$ t (abscissa) for first order reaction	2. Zero
R. $\left(-\frac{dc}{dt}\right)\upsilon sC$ for Zero order reaction	3. $-k$
S.ln $\left(-\frac{dc}{dt}\right)$ $\upsilon s$ ln C for first order reaction	4. $-\frac{k}{2.303}$

first order reaction
$\begin{array}{cccc}P& Q& R& S\end{array}$

• A. $\begin{array}{cccc}4& 3& 2& 1\end{array}$
• B. $\begin{array}{cccc}3& 4& 2& 1\end{array}$
• C. $\begin{array}{cccc}2& 4& 3& 1\end{array}$
• D. $\begin{array}{cccc}3& 2& 4& 1\end{array}$

Answer 1

Answer: (B)

(P) For a zero order reaction, $C=C_0-kt$
(Q) For a first order reaction , log C=$log{C}_0-\frac{k}{2.303}\times t$
(R) For a zero order reaction, $-\frac{dc}{dt}=k$ (constant)
Hence, slope of $-\frac{dc}{dt}\nu sC=0$
(S) For a first order reaction, $-\frac{dc}{dt}=kc,$
ln $\left(-\frac{dc}{dt}\right)=lnk+lnC.$
Hence, plot of ln $\left(-\frac{dc}{dt}\right)$ against ln C will have slope equal to unity.