Unit 6 Stoichiometry

Mole = _______

• Unit of measurement for the amount of a substance

• A type of animal

• A skin blemish

• A spy or informant

Tags

NGSS.HS-PS1-7

Avogadro’s number = _______

• 6.022 x 10^23; the number of particles in 1 mole of a substance

• 3.014 x 10^23; the number of particles in 1 mole of a substance

• 6.022 x 10^22; the number of particles in 1 mole of a substance

• 1.022 x 10^23; the number of particles in 1 mole of a substance

Tags

NGSS.HS-PS1-7

Molar mass = _______

• The mass of one mole of pure substance measured in g/mol

• The volume of one mole of pure substance measured in L/mol

• The density of one mole of pure substance measured in kg/mol

• The temperature of one mole of pure substance measured in K/mol

Formula mass = _______

• The sum of the average atomic masses of a compound’s elements measured in amu

• The product of the atomic numbers of a compound’s elements

• The difference between the highest and lowest atomic masses in a compound

• The average of the atomic masses of a compound’s elements

Percent composition = _______

• Percentage based on mass of each element in a compound

• Percentage based on volume of each element in a compound

• Ratio of the number of atoms of each element in a compound

• Molar mass of the compound

Explain the relationship between the following terms; mole, Avogadro’s number, and molar mass. Include what each is used for.

• Mole is a unit of measurement, Avogadro’s number is the number of particles in a mole, and molar mass is the mass of one mole of a substance.

• Mole is the mass of a substance, Avogadro’s number is a constant used in physics, and molar mass is the volume of a mole.

• Mole is a chemical element, Avogadro’s number is the number of atoms in a molecule, and molar mass is the weight of a single atom.

• Mole is a type of chemical reaction, Avogadro’s number is the number of molecules in a reaction, and molar mass is the energy produced.

Differentiate between the empirical and molecular formula of a compound and explain how it applies differently to ionic vs. covalent compounds.

• Empirical formula represents the simplest whole-number ratio of elements in a compound, while molecular formula shows the actual number of atoms of each element in a molecule. This distinction is more relevant for covalent compounds than ionic compounds.

• Empirical formula and molecular formula are the same for all compounds, regardless of whether they are ionic or covalent.

• Empirical formula is used only for ionic compounds, while molecular formula is used only for covalent compounds.

• Empirical formula is a theoretical concept and does not apply to real compounds.

Find the percent composition of a compound and use percent composition to determine the empirical and molecular formulas for an unknown compound. Outline the method.

• Determine the mass of each element in the compound, calculate the moles of each element, find the mole ratio, and derive the empirical formula.

• Use the molecular weight to find the percent composition directly.

• Assume a 100g sample to simplify calculations, then find the empirical formula.

• Use the percent composition to directly write the molecular formula.

How many molecules are in 2.00 mol of CO₂?

• 1.20 x 10²⁴ molecules

• 6.022 x 10²³ molecules

• 2.00 x 10²⁴ molecules

• 3.01 x 10²³ molecules

What is the mass, in grams, of 7.18 mol of calcium carbonate?

• 500.5 grams

• 718 grams

• 1000 grams

• 1799 grams