Chemistry 1st Paper MCQ-Rajshahi Board-2023

1. When an electron moves from an infinite distance energy level to the fourth energy level the radiated ray is in which series?

2. Which radiation has the longest wave length?

3. What is the set of quantum numbers for the electron in the outermost energy level of a $\mathrm{Cr}$ atom?

4. Which block has more nonmetals in the periodic tale?

5. $\mathrm{X}_{2}(\mathrm{~g})+3 \mathrm{Y}_{2}(\mathrm{~g}) \rightleftharpoons 2 \mathrm{XY}_{3}(\mathrm{~g}) ; \Delta \mathrm{H}=-\mathrm{ve}$

At the equilibrium of the reaction, the concentration of $\mathrm{X}_{2}, \mathrm{Y}_{2}$ and $\mathrm{XY}_{3}$ are respectively $0.18,0.56$ and $0.12 \mathrm{~mol} \mathrm{~L}^{-1}$.

Value of Kc of the reaction-