Answer:
121.1g
Step-by-step explanation:
First, we need to convert the number of molecules of NaCl to moles (n) by dividing by Avagadro number
That is, n = number of molecules ÷ 6.02 × 10²³
n = 1.25 X 10²⁴ ÷ 6.02 × 10²³
n = 1.25/6.02 × 10^ (24-23)
n = 0.207 × 10¹
n = 2.07moles
Using the formula; mole = mass ÷ molar mass
Molar mass of NaCl = 23 + 35.5 = 58.5g/mol
mass = molar mass × mole
mass = 58.5 × 2.07
mass = 121.1g