When a strip of zinc is placed in a solution of silver nitrate, Zn replaces Ag to form zinc nitrate, and metallic silver is formed. How many moles of silver will be generated if 1.30 moles of zinc is placed into the silver nitrate solution? 2AgNO3 + Zn → 2Ag + Zn(NO3)2

you can use stoichiometry which is taking the number in from of each substance and using it as a molar ratio(ones that don't have a number actually have a 1 in front

so 2AgNO3 + 1 Zn -> 2 Ag + Zn (NO3)2

The ratio is of moles of Zn to moles of Silver is 1:2 so for every 1 mole of Zn there's 2 moles of Ag

1.3 × 2 = 2.6 moles of Ag are made

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.