Mole calculations

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What is a mole in chemistry?

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A mole is a unit of measurement used to express amounts of a chemical substance. It is defined as the amount of substance that contains as many entities (atoms, molecules, etc.) as there are in 12 grams of carbon-12.

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How do you calculate the number of atoms in a sample?

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To calculate the number of atoms in a sample, use the formula: Number of atoms = moles × Avogadro's number (6.02 x 10^23).

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What is the empirical formula?

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The empirical formula is the simplest whole-number ratio of the elements in a compound.

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How do you determine the empirical formula from percentage composition?

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1. Convert percentages to grams. 2. Convert grams to moles. 3. Divide by the smallest number of moles to find the ratio.

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What is the molecular formula?

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The molecular formula shows the actual number of atoms of each element in a molecule, which may be a multiple of the empirical formula.

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How do you calculate the percent composition by mass of an element in a compound?

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Percent composition = (mass of element in 1 mole of compound / molar mass of compound) × 100%.

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What is Avogadro's number?

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Avogadro's number is 6.02 x 10^23, which is the number of atoms, molecules, or particles in one mole of a substance.

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How do you convert grams to moles?

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To convert grams to moles, use the formula: Moles = mass (g) / molar mass (g/mol).

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What is the significance of the molar mass in mole calculations?

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Molar mass is the mass of one mole of a substance and is used to convert between grams and moles.

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How do you find the number of moles from a given mass?

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Number of moles = mass (g) / molar mass (g/mol).