Answer:
3.01 × 10^24 atoms of vitamin D
Explanation:
The number of atoms, molecules or ions present in a substance is given by the Avogadro's number which is 6.02 × 10^23.
Hence;
1 molecule of vitamin D contains 6.02 ×10^23 atoms
5 molecules of vitamin D contains 5 × 6.02 ×10^23/1
= 3.01 × 10^24 atoms of vitamin D
Answer:
Solution's mass = 200.055 g
[PbSO₄] = 275 ppm
Explanation:
Solute mass = 0.055 g of lead(II) sulfate
Solvent mass = 200 g of water
Solution mass = Solvent mass + Solution mass
0.055 g + 200 g = 200.055 g
ppm = μg of solute / g of solution
We convert the mass of solute from g to μg
0.055 g . 1×10⁶ μg/ 1g = 5.5×10⁴μg
5.5×10⁴μg / 200.055 g = 275 ppm
ppm can also be determined as mg of solute / kg of solution
It is important that the relation is 1×10⁻⁶
Let's verify: 0.055 g = 55 mg
200.055 g = 0.200055 kg
55 mg / 0.200055 kg = 275 ppm
