Question

Please calculate the theoretical mass of the salt needed to prepare 25mL solution of 0.1M concentration.

Possible salts are KCl, KBr, KI, NaCl, NaBr, NaI. You must calculate the mass of each possible salt.

Answer 1

Molarity = Moles / V in L

0.1 = Moles *1000 / 25

Moles = 0.0025

Mass of KCl = Moles *Molar mass = 0.0025*74.55 = 0.186375 gms

Mass of KBr = Moles *Molar mass = 0.0025*119 = 0.2975 gms

Mass of KI =  Moles *Molar mass = 0.0025**166 = 0.415 gms

Mass of NaCl =  Moles *Molar mass = 0.0025*58.44 = 0.146 gms

Mass of NaBr =  Moles *Molar mass = 0.0025*102.894 = 0.257 gms

Mass of NaI =  Moles *Molar mass = 0.0025*150 = 0.375 gms