Answer:
3.00x10²⁵ atoms of chromiun
Explanation:
The formula of aluminum dichromate is Al₂(Cr₂O₇)₃.
In the formula it is seen that for each molecule of the compound, we have 6 chromium atoms, so in one mole of it, there are 6 moles of chromium. With this information you can calculate the amount of chromium atoms using Avogadro's number.
Since we know that in one mole there are 6.02x10²³ molecules of aluminum dichromate, and in each molecule there are 6 chromium atoms, so the following relationship can be established:
1 mole Al₂(Cr₂O₇)₃ _____ 6 x (6.02x10²³) Chrome atoms
8.3 moles _____ X = 3.00x10²⁵ atoms
Calculation:
8.3 moles x [6 x (6.02x10²³)] / 1 mol = 2.9979x10²⁵ atoms ≅ 3.00x10²⁵atoms
The answer, then, is that there are 3.00x10²⁵ chromium atoms in 8.3 moles of aluminum dichromate
