Ammonical ${\mathrm{AgNO}}_3$ give white ppt. after reaction with any compound that this reflect the presence of:

${\mathrm{AgNO}}_3/{\mathrm{NH}}_4\mathrm{OH}$- Tollent's Reagents 

$\mathrm{R}-\mathrm{C} -\underset{{\mathrm{AgNO}}_{3/{\mathrm{NH}}_4\mathrm{OH} }}{\mathrm{T}.\mathrm{R}}\to \mathrm{R}-\stackrel{\stackrel{\mathrm{O}}{\parallel }}{\mathrm{C}}-\mathrm{OH} + \underset{\mathrm{Silver} \mathrm{mirror}}{\mathrm{Ag}\downarrow } - \mathrm{CHO}$

$\mathrm{R}-\mathrm{C}\equiv \mathrm{C}-\mathrm{H}+{\mathrm{AgNO}}_3/{\mathrm{NH}}_4\mathrm{OH} \to \mathrm{R}-\mathrm{C}\equiv \mathrm{C} -\underset{\mathrm{white} \mathrm{ppt}.}{\mathrm{Ag}}$