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Calculate the mass of 6.023 x 10^4 molecules of manganese (IV) oxide(careful of your molecular formula).

User Govind Gupta
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1 Answer

11 votes
11 votes

1) First, we need to transform molecules into moles. For this, we use the avogadro constant:

6.023 × 10²³ moleculas ----- 1 mol

6.023 × 10⁴ molecules ------ x mol

x = 6.023 × 10⁴/ 6.023 × 10²³

x = 1 × 10⁻¹⁹ mol

2) Now we need to find the molecular formula of manganese (IV) oxide to find out its molar mass and transform 1 × 10⁻¹⁹ mol into grams (mass of it). The molecular formula of manganese (IV) oxide is MnO₂. So its molar mass: 54.94 + (2x16) = 86.94 g/mol

Now we use the following equation to find out the mass:

mass = moles × molar mass

mass = 1 × 10⁻¹⁹ × 86.94

mass = 86.94 × 10⁻¹⁹

mass = 8.7 × 10⁻¹⁸ grams

Answer: 8.7 × 10⁻¹⁸ grams

User Najih Km
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