Molar Mass and Formula Mass Calculations

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What is Molar Mass?

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The mass of one mole of a substance, typically expressed in grams per mole (g/mol).

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How do you calculate Molar Mass?

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Add the atomic masses of all atoms in a molecule based on its chemical formula.

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What is the difference between Molar Mass and Formula Mass?

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Molar mass refers to the mass of one mole of a substance, while formula mass is the sum of the atomic masses of all atoms in a formula, regardless of the amount.

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What is an Empirical Formula?

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The simplest whole-number ratio of atoms of each element in a compound.

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How do you determine the Empirical Formula from percentage composition?

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Convert the percentages to grams, then to moles, and find the simplest ratio of the moles.

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What is a Molecular Formula?

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A formula that shows the actual number of atoms of each element in a molecule.

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How do you find the Molecular Formula from the Empirical Formula?

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Divide the molecular mass by the empirical formula mass and multiply the subscripts in the empirical formula by that ratio.

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What are the units for Molar Mass?

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Grams per mole (g/mol).

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What is the formula mass of K2S?

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110.3 g/mol.

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What is the empirical formula for 40.05% S and 59.95% O?

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SO3.