Explanation:
Molar mass of Potassium Nitrate:-
\begin{gathered}\\ \large\sf\longmapsto KNO_3\end{gathered}
⟼KNO
3
\begin{gathered}\\ \large\sf\longmapsto 39u+14u+3(16u)\end{gathered}
⟼39u+14u+3(16u)
\begin{gathered}\\ \large\sf\longmapsto 53u+48u\end{gathered}
⟼53u+48u
\begin{gathered}\\ \large\sf\longmapsto 101u\end{gathered}
⟼101u
\begin{gathered}\\ \large\sf\longmapsto 101g/mol\end{gathered}
⟼101g/mol
Now
\boxed{\sf No\:of\:moles=\dfrac{Given\:mass}{Molar\:mass}}
Noofmoles=
Molarmass
Givenmass
\begin{gathered}\\ \large\sf\longmapsto No\:of\:moles=\dfrac{0.565}{101}\end{gathered}
⟼Noofmoles=
101
0.565
\begin{gathered}\\ \large\sf\longmapsto No\:of\:moles=0.005mol\end{gathered}
⟼Noofmoles=0.005mol
We know
\boxed{\sf Molarity=\dfrac{Moles\:of\:solute}{Vol\:of\:Solution\:in\:L}}
Molarity=
VolofSolutioninL
Molesofsolute
\begin{gathered}\\ \large\sf\longmapsto Molarity=\dfrac{0.005}{\dfrac{250}{1000}L}\end{gathered}
⟼Molarity=
1000
250
L
0.005
\begin{gathered}\\ \large\sf\longmapsto Molarity=\dfrac{0.005}{0.250}\end{gathered}
⟼Molarity=
0.250
0.005
\begin{gathered}\\ \large\sf\longmapsto Molarity=0.02M\end{gathered}
⟼Molarity=0.02M