Answer:
6.46×10²² formula units
Explanation:
From the question given above, the following data were obtained:
Mass of MgCl₂ = 10.2 g
Number of formula units =?
From Avogadro's hypothesis,
1 mole of MgCl₂ = 6.02×10²³ formula units
But,
1 mole of MgCl₂ = 24 + (35.5×2) = 24 + 71 = 95 g
Thus, we can say:
95 g of MgCl₂ = 6.02×10²³ formula units
Finally, we shall determine the formula units in 10.2 g MgCl₂. This can be obtained as follow:
95 g of MgCl₂ = 6.02×10²³ formula units
Therefore,
10.2 g of MgCl₂ = (10.2 × 6.02×10²³) / 95
10.2 g of MgCl₂ = 6.46×10²² formula units
Thus, 10.2 g of MgCl₂ contains 6.46×10²² formula units
