Answer:
Second option is the right one
Explanation:
The ppm concentration indicates a relation between the mass of solute in mass of solution, where the units have a quotient of 1×10⁻⁶.
You can think the units as mg/kg or μg / g
We assume the solvent's mass, as the solution's mass
ppm = mass solute/mass solution × 10⁶
ppm = 1.56×10⁻⁵ g NaCl . 10⁶ /25 g
ppm = 0.62
