Step-by-step explanation:
Find moles first
moles = number of particles/ 6×10^23
= 7.52 ×10^25 / 6×10^23
=125.33
calculate molar mass
(1×14) +(3×1) =17
convert to mass
mass= moles × molar mass
=125.33 × 17
=2130.67g
This is a pretty big value usually it's smaller but I'd assume it's because the number of particles was large.