Answer:
1. 1.80x10⁻⁵ (w/w %).
2. 1.80x10⁻⁴ parts per thousand
3. 0.18 parts per million
Explanation:
The solution contains 45.1μg / 250mL.
1. Weight percent (100 times mass in grams of solute per gram of solution, as there are 250mL of water = 250g):
45.1x10⁻⁶g / 250g * 100 =
1.80x10⁻⁵ (w/w %)
2. Parts per thousand (mg of solute per g of solution).
45.1μg * (1x10⁻³mg / 1μg) = 0.0451mg.
0.0451mg / 250g =
1.80x10⁻⁴ parts per thousand
3. Parts per million (μg of solute per g of solution):
45.1μg / 250g =
0.18 parts per million
