The Mole and Formulas

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What is a mole in chemistry?

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A mole is a unit of measurement used to express the amount of a 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 moles from atoms?

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

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What is the molar mass of an element?

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The molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is numerically equivalent to the atomic or molecular weight of the substance.

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How do you find the molar mass of a compound?

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To find the molar mass of a compound, sum the molar masses of all the atoms in its chemical formula.

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What is percent composition by mass?

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Percent composition by mass is the percentage by mass of each element in a compound, calculated by dividing the mass of the element by the total mass of the compound and multiplying by 100.

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How do you calculate the mass of a substance from moles?

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To calculate the mass of a substance from moles, use the formula: Mass (g) = Number of moles x Molar mass (g/mol).

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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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What is the molar mass of sodium chloride (NaCl)?

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The molar mass of sodium chloride (NaCl) is 58.5 g/mol.

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How many grams are in 1 mole of carbon (C)?

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1 mole of carbon (C) has a mass of 12 grams.

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What is the mass of 0.5 moles of water (H2O)?

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The mass of 0.5 moles of water (H2O) is 9 grams (molar mass of H2O is 18 g/mol).