Chapter 11: The Mole Notes Review

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2. 6.02x10²³ is known as:

Avocado's Number

Abracadabra's Number

Avodangro's Number

Avogadro's Number

6.02x10^23 is known as Avogadro's Number. It represents the number of atoms, molecules, or particles in one mole of a substance. This constant is named after the Italian scientist Amedeo Avogadro, who proposed the concept of Avogadro's law, stating that equal volumes of gases at the same temperature and pressure contain an equal number of particles. Avogadro's Number is widely used in chemistry and is essential for calculations involving the mole and stoichiometry.

Explanation

6.02x10^23 is known as Avogadro's Number. It represents the number of atoms, molecules, or particles in one mole of a substance. This constant is named after the Italian scientist Amedeo Avogadro, who proposed the concept of Avogadro's law, stating that equal volumes of gases at the same temperature and pressure contain an equal number of particles. Avogadro's Number is widely used in chemistry and is essential for calculations involving the mole and stoichiometry.

3. SI unit used to measure the amount of a substance. (Like a dozen).

The SI unit used to measure the amount of a substance is the mole (mol). The mole is similar to a dozen, as it represents a specific number of entities (in this case, atoms, molecules, or ions) just like a dozen represents a specific number of items. The mole is a fundamental unit in chemistry and is used to quantify the amount of a substance in a given sample. The term "Mole" is simply another way of referring to the unit "mol".

Explanation

The SI unit used to measure the amount of a substance is the mole (mol). The mole is similar to a dozen, as it represents a specific number of entities (in this case, atoms, molecules, or ions) just like a dozen represents a specific number of items. The mole is a fundamental unit in chemistry and is used to quantify the amount of a substance in a given sample. The term "Mole" is simply another way of referring to the unit "mol".

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4. Assume you wlaways have ____ grams when calculating percentages of elements in a compound.

The given correct answer options all represent the same numerical value, which is 100. When calculating percentages of elements in a compound, it is assumed that you always have 100 grams as the base unit of measurement. This allows for easy comparison and calculation of the percentage composition of each element in the compound.

Explanation

The given correct answer options all represent the same numerical value, which is 100. When calculating percentages of elements in a compound, it is assumed that you always have 100 grams as the base unit of measurement. This allows for easy comparison and calculation of the percentage composition of each element in the compound.

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5. Mass in grams of one mole of any pure substance. (g/mol) Equal to the atomic mass.

The molar mass of a substance is the mass in grams of one mole of that substance. It is equal to the atomic mass of the substance. Molar mass is used to convert between the mass of a substance and the number of moles of that substance, and it is an important concept in chemistry for calculating various quantities in chemical reactions.

Explanation

The molar mass of a substance is the mass in grams of one mole of that substance. It is equal to the atomic mass of the substance. Molar mass is used to convert between the mass of a substance and the number of moles of that substance, and it is an important concept in chemistry for calculating various quantities in chemical reactions.

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6. To find the molar mass of a molecule you:

Add up the pieces.

Multiply the pieces.

Subtract the pieces.

Divide the pieces.

To find the molar mass of a molecule, you need to add up the masses of all the individual atoms (pieces) in the molecule. Each element has a specific atomic mass, and by adding them together, you can determine the molar mass of the entire molecule. Multiplying, subtracting, or dividing the pieces would not give you the correct answer for the molar mass.

Explanation

To find the molar mass of a molecule, you need to add up the masses of all the individual atoms (pieces) in the molecule. Each element has a specific atomic mass, and by adding them together, you can determine the molar mass of the entire molecule. Multiplying, subtracting, or dividing the pieces would not give you the correct answer for the molar mass.

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8. If you have C6H12O6; What is the empirical formula?

The empirical formula represents the simplest ratio of atoms in a compound. In this case, the compound C6H12O6 can be simplified by dividing all the subscripts by the greatest common factor, which is 6. After simplification, we get CH2O as the empirical formula.

Explanation

The empirical formula represents the simplest ratio of atoms in a compound. In this case, the compound C6H12O6 can be simplified by dividing all the subscripts by the greatest common factor, which is 6. After simplification, we get CH2O as the empirical formula.

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9. To get the ratios of the empirical formula you divide by the _____ number.

To determine the ratios of the empirical formula, you divide by the smallest number. This is because the empirical formula represents the simplest ratio of atoms in a compound, and the smallest number in the ratio indicates the lowest whole number ratio of atoms present. Therefore, dividing by the smallest number allows us to obtain the correct ratios of the empirical formula.

Explanation

To determine the ratios of the empirical formula, you divide by the smallest number. This is because the empirical formula represents the simplest ratio of atoms in a compound, and the smallest number in the ratio indicates the lowest whole number ratio of atoms present. Therefore, dividing by the smallest number allows us to obtain the correct ratios of the empirical formula.

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11. You have the substance C6H12O6. You are trying to find the number of oxygen ions in 60 grams of the substancce. Fill in the blank. 60 gC6H12O6 1 mol ? O -------------------- X ------------- X --------------------- 1 180.155 g 1 mol C6H12O6

In the given calculation, we are converting the mass of C6H12O6 (60g) to the number of oxygen ions. Since the molar mass of C6H12O6 is 180.155g/mol and there are 6 oxygen atoms in one molecule of C6H12O6, we can calculate the number of moles of C6H12O6 by dividing the mass (60g) by the molar mass (180.155g/mol). Since there are 6 oxygen atoms in one molecule of C6H12O6, the number of oxygen ions is equal to the number of moles of C6H12O6 multiplied by 6. Therefore, the answer is 6.

Explanation

In the given calculation, we are converting the mass of C6H12O6 (60g) to the number of oxygen ions. Since the molar mass of C6H12O6 is 180.155g/mol and there are 6 oxygen atoms in one molecule of C6H12O6, we can calculate the number of moles of C6H12O6 by dividing the mass (60g) by the molar mass (180.155g/mol). Since there are 6 oxygen atoms in one molecule of C6H12O6, the number of oxygen ions is equal to the number of moles of C6H12O6 multiplied by 6. Therefore, the answer is 6.

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12. Avogadro's number can be used to show: Check all that apply.

Atoms

Compounds

Molecules

Mass

Moles

Formula Units

Avogadro's number, also known as the Avogadro constant, is a fundamental constant in chemistry that represents the number of particles (atoms, molecules, or formula units) in one mole of a substance. Therefore, it can be used to show the number of atoms, molecules, and formula units in a given amount of substance. It is not directly related to compounds, mass, or moles, so these options are not applicable.

Explanation

Avogadro's number, also known as the Avogadro constant, is a fundamental constant in chemistry that represents the number of particles (atoms, molecules, or formula units) in one mole of a substance. Therefore, it can be used to show the number of atoms, molecules, and formula units in a given amount of substance. It is not directly related to compounds, mass, or moles, so these options are not applicable.

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