Moles Flashcard 2

Front

What is a mole in chemistry?

Back

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.

Front

How many atoms are in one mole of a substance?

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One mole of any substance contains 6.02 x 10^23 entities, known as Avogadro's number.

Front

What is an empirical formula?

Back

An empirical formula is the simplest whole-number ratio of atoms of each element in a compound.

Front

What is the difference between an empirical formula and a molecular formula?

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An empirical formula shows the simplest ratio of elements in a compound, while a molecular formula shows the actual number of atoms of each element in a molecule.

Front

How do you calculate the number of moles from grams?

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To calculate the number of moles, divide the mass of the substance (in grams) by its molar mass (in g/mol). Formula: Moles = Mass (g) / Molar Mass (g/mol).

Front

What is a hydrate?

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A hydrate is a compound that contains water molecules within its structure.

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How do you determine the empirical formula from percentage composition?

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Convert the percentage of each element to grams, then to moles, and find the simplest whole-number ratio of the moles.

Front

What is the molar mass of water (H2O)?

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The molar mass of water is approximately 18.02 g/mol.

Front

What is the significance of Avogadro's number?

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Avogadro's number allows chemists to convert between the number of atoms/molecules and the amount of substance in moles.

Front

How many grams are in one mole of glucose (C6H12O6)?

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One mole of glucose weighs approximately 180.18 grams.