Write about the Finkelstein and Swarts reactions.

(N/A) Finkelstein Reaction (Preparation of Alkyl Iodides from Alkyl Chlorides/Bromides): Alkyl chlorides or bromides are reacted with $NaI$ in dry acetone to form alkyl iodides.
"The reaction of alkyl chlorides or bromides with $NaI$ in dry acetone to form alkyl iodides is known as the Finkelstein reaction."
Reaction: $R-X + NaI \xrightarrow{\text{dry acetone}} R-I + NaX(s)$
(where $X = Cl, Br$).
In this reaction,$NaCl$ or $NaBr$ precipitates out,which shifts the equilibrium forward according to Le Chatelier's principle.
$(b)$ Swarts Reaction (Preparation of Alkyl Fluorides from Alkyl Chlorides/Bromides): Alkyl chlorides or bromides are heated with metallic fluorides such as $AgF$,$Hg_2F_2$,$CoF_2$,or $SbF_3$.
"The reaction of alkyl chlorides or bromides with metallic fluorides to form alkyl fluorides is known as the Swarts reaction."
Reaction: $H_3C-Br + AgF \rightarrow H_3C-F + AgBr$