1
KCET 2026
MCQ (Single Correct Answer)
+1
-0
For a reaction having three steps, the overall rate constant is $k = \dfrac{k_1 k_2}{k_3}$. The values of $E_{a_1}, E_{a_2}$ and $E_{a_3}$ (activation energies stepwise) are $40$, $50$ and $60$ kJ mol$^{-1}$ respectively. Then the overall $E_a$ (activation energy) of the reaction is ____
A
$30\text{ kJ mol}^{-1}$
B
$40\text{ kJ mol}^{-1}$
C
$50\text{ kJ mol}^{-1}$
D
$60\text{ kJ mol}^{-1}$
2
KCET 2026
MCQ (Single Correct Answer)
+1
-0
Which one of the following graph is not applicable for a 1st order reaction ($R \rightarrow P$)?
A
B
C
D
3
KCET 2026
MCQ (Single Correct Answer)
+1
-0
The calculated spin only magnetic moment of $\text{Cr}^{2+}$ ion is
A
$3.87$ BM
B
$4.90$ BM
C
$5.92$ BM
D
$2.84$ BM
4
KCET 2026
MCQ (Single Correct Answer)
+1
-0
The highest oxidation state of manganese in fluoride is $+4$ ($\text{MnF}_4$), but the highest oxidation state in oxides is $+7$ ($\text{Mn}_2\text{O}_7$), because
A
Fluorine is more electronegative than oxygen
B
Fluorine possesses d-orbitals
C
Fluorine stabilises lower oxidation state
D
In covalent compounds, fluorine can form single bond only, while oxygen forms double bond