How many chromium atoms are in 3.56 x 10^-21 moles of potassium chromate?

21.44× 10² atoms

Explanation:

Number of chromium atoms = ?

Moles of potassium chromate = 3.56 × 10⁻²¹ mol

Solution:

1 mole of K₂CrO₄ contain 1 mole of Cr.

3.56 × 10⁻²¹ moles of K₂CrO₄ contain 3.56 × 10⁻²¹  moles of Cr.

Number of atoms of Cr:

1 mole contain 6.022× 10²³ atoms

3.56 × 10⁻²¹ mole ×  6.022× 10²³ atoms / 1mol

21.44× 10² atoms or 2144 atoms

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