Moles and Avogadro's Number

What is the significance of Avogadro's number in chemistry?

• It allows chemists to count particles by weighing them.

• It determines the speed of chemical reactions.

• It measures the temperature of a substance.

• It indicates the color of a chemical compound.

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What is Avogadro's number?

• 6.02 x 10^23 particles per one mole of a substance

• 3.01 x 10^23 particles per one mole of a substance

• 1.22 x 10^24 particles per one mole of a substance

• 9.81 x 10^22 particles per one mole of a substance

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How do you calculate the number of molecules in a given number of moles?

• Multiply the number of moles by Avogadro's number (6.02 x 10^23).

• Add the number of moles to Avogadro's number (6.02 x 10^23).

• Divide the number of moles by Avogadro's number (6.02 x 10^23).

• Multiply the number of moles by the molar mass of the substance.

Define molar mass.

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

• The weight of a single atom of an element, measured in atomic mass units (amu).

• The total mass of all the atoms in a molecule, divided by the number of molecules.

• The mass of a liquid at its boiling point, measured in liters.

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What is the relationship between moles and molar mass?

• Moles are a measure of quantity, while molar mass is the mass of one mole of a substance.

• Moles are used to measure temperature, while molar mass is the weight of a substance in grams.

• Moles represent the volume of a gas, while molar mass is the density of a substance.

• Moles are a measure of pressure, while molar mass is the amount of energy in a substance.

How many molecules are in 5.2 moles of water?

• 2.5104 x 10^24 molecules

• 3.1304 x 10^24 molecules

• 1.2048 x 10^24 molecules

• 4.5600 x 10^24 molecules

What is the molar mass of AuCl3?

• 298.2 g

• 303.3 g

• 310.5 g

• 295.0 g

What is the unit for measuring the amount of substance?

• gram (g)

• liter (L)

• mole (mol)

• meter (m)

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NGSS.HS-PS1-7

What is the formula for calculating the number of particles in a sample?

• Number of particles = number of moles x Avogadro's number.

• Number of particles = mass x molar mass.

• Number of particles = volume x density.

• Number of particles = number of moles x gas constant.

What is the molar mass of NaCl?

• 54.44 g/mol

• 58.45 g/mol

• 60.01 g/mol

• 62.50 g/mol