| A unit used to measure the amount of a substance, where 1 mole contains 6.02 × 10^23 particles. | Moles |
| What is the purpose of using moles? | Moles are used to measure the amount of a substance. |
| The number of particles (atoms, molecules, ions, etc.) in one mole of a substance, which is approximately 6.02 × 10^23. | Avogadro Constant |
| What is the significance of the Avogadro constant? | The Avogadro constant represents the number of particles in one mole of a substance and remains constant regardless of the type of particle being measured. |
| How many carbon atoms are present in 1 mole of carbon? | 1 mole of carbon contains approximately 6.02 × 10^23 carbon atoms. |
| How many carbon dioxide molecules are present in 1 mole of carbon dioxide gas? | Equally, 1 mole of carbon dioxide gas will contain 6.02 × 10^23 carbon dioxide molecules. |
| The mass of one mole of a substance in grams, which is equal to its relative formula mass (Mr). | Mass of 1 Mole |
| What is the relationship between the mass of 1 mole of a substance and its relative formula mass? | The mass of 1 mole of a substance in grams is equal to its relative formula mass (Mr). |
| The sum of the atomic masses of all the atoms in a formula unit of a substance. | Relative Formula Mass (Mr) |
| A molecule composed of two oxygen atoms bonded together, forming the chemical formula O2. | Oxygen Molecule (O2) |
| What is the mass of 1 mole of O2 molecules? | O2 has an Mr of 32, so the mass of 1 mole of O2 molecules is exactly 32 grams. |
| A molecule composed of two hydrogen atoms and one oxygen atom bonded together, forming the chemical formula H2O. | Water Molecule (H2O) |
| What is the mass of 1 mole of H2O molecules? | A mole of H2O has an Mr of 18, so the mass of 1 mole of H2O molecules is exactly 18 grams. |
| The number of particles (atoms, molecules, ions, etc.) in one mole of a substance, approximately equal to 6.02 × 10^23. | Avogadro Constant |
| What does it mean that 32 grams of O2 contain the same number of molecules as 18 grams of H2O? | It means that both samples contain Avogadro's number of molecules, which is approximately 6.02 × 10^23 particles. |
| The sum of the atomic masses of all the atoms in a formula unit of a substance. | Mr (Relative Formula Mass) |
| How can the Mr be used to calculate the number of moles in a given mass? | If you know the mass of a substance, you can use the Mr to calculate how many moles it contains. |
| The process of using the mass of a substance and its Mr to determine the number of moles present. | Mass-to-Moles Calculation |
| How can the formula be rearranged and used to find the mass in grams of a substance? | The formula can be rearranged to find the mass in grams of a substance by multiplying the number of moles by the Mr. |
| A molecule composed of two nitrogen atoms bonded together, forming the chemical formula N2. | Nitrogen Molecule (N2) |
| How many moles are in 130 g of nitrogen (N2)? | 4.6 mol. The number of moles in 130 g of nitrogen (N2) can be calculated using its Mr and the given mass. |
| A molecule composed of two oxygen atoms bonded together, forming the chemical formula O2. | Oxygen Molecule (O2) |
| What is the mass of 8 moles of oxygen molecules (O2)? | 256 g. The mass of 8 moles of oxygen molecules (O2) can be calculated using its Mr and the given number of moles. |
| The number of particles (atoms, molecules, ions, etc.) in one mole of a substance, approximately equal to 6.02 × 10^23. | Avogadro Constant |
| How many particles are in 2 moles of a substance? | 2 moles of a substance contain 2 times Avogadro's constant, which is 2 × 6.02 × 10^23 particles. |
| The equation used to calculate the number of particles, given the number of moles of a substance. | Particle Calculation Equation |
| What is the equation to calculate the number of particles? | The equation to calculate the number of particles is: Number of particles = Number of moles × Avogadro's constant. |
| A molecule composed of two hydrogen atoms and one oxygen atom bonded together, forming the chemical formula H2O. | Water Molecule (H2O) |
| How many particles are in 12.5 moles of water? | 12.5 moles of water contain 12.5 times Avogadro's constant, which is 12.5 × 6.02 × 10^23 particles = 7.525 × 10^24 particles. |
| What is the equation to calculate the number of moles from the number of particles? | The equation to calculate the number of moles from the number of particles is: Number of moles = Number of particles / Avogadro's constant. |
| A metallic element with atomic number 30 and symbol Zn. | Zinc (Zn) |
| How many moles are in a piece of zinc containing 4.50 × 10^24 particles? | The number of moles in a piece of zinc containing 4.50 × 10^24 particles can be calculated by dividing the number of particles by Avogadro's constant. 4.5 × 10^24 / 6.02 × 10^23 = 7.48 moles. |
| The process of determining the number of particles in a substance, often based on its mass and Avogadro's constant. | Number of Particles Calculation |
| How can the number of particles in a substance be calculated? | The number of particles in a substance can be calculated by first determining the number of moles using the equation moles = mass / Mr, then multiplying the number of moles by Avogadro's constant. |
| A metallic element with atomic number 13 and symbol Al. | Aluminium (Al) |
| How many particles are in 50 g of aluminium? | To calculate the number of particles in 50 g of aluminium, first determine the number of moles using the equation moles = mass / Mr, (1.85 moles of aluminium (50/27 = 1.85 mol)) then multiply the number of moles by Avogadro's constant (1.85 × 6.02 × 10^23 = 1.11 × 10^24 particles). |
| How can mass be calculated from a given number of particles? | Mass can be calculated by first determining the number of moles using the equation moles = number of particles / Avogadro's constant, then multiplying the number of moles by the relative formula mass (Mr). |
| A dense, soft, yellow, and highly valuable metal, symbolized by Au on the periodic table. | Gold (Au) |
| How many moles of gold are in 3.30 × 10^24 particles? | To calculate the number of moles of gold in 3.30 × 10^24 particles, divide the number of particles by Avogadro's constant. (3.30 × 1024 / 6.02 × 1023 = 5.48 mol) |
| What is the mass of 3.30 × 10^24 particles of gold? | To calculate the mass of 3.30 × 10^24 particles of gold, first determine the number of moles (3.30 × 1024 / 6.02 × 1023 = 5.48 mol), then multiply the number of moles by the Mr (molar mass) of gold (5.48 × 197 = 1080). |
| The cessation of a chemical reaction upon complete consumption of one of the reactants. | Chemical Reaction Termination |
| What happens as soon as one of the reactants in a chemical reaction is fully consumed? | The chemical reaction stops. |
| The reactant that is consumed first in a chemical reaction, thereby limiting the amount of product that can be formed. | Limiting Reactant |
| What is the limiting reactant in a chemical reaction? | The limiting reactant is the reactant that gets used up first, determining the amount of product that can be formed. |
| The reactant that remains unconsumed after a chemical reaction has reached completion due to the presence of a limiting reactant. | Excess Reactant |
| What are the reactants called that are left over after a chemical reaction? | The reactants left over after a chemical reaction are called excess reactants. |
| The quantitative relationship between the amounts of reactants and products in a chemical reaction, determined by the balanced chemical equation. | Reaction Stoichiometry |
| What controls the mass of product that can be formed in a chemical reaction? | The mass of product formed in a chemical reaction is controlled by the mass of the limiting reactant. |
| A deliberate approach in a reaction with 2 reactants where one reactant is intentionally used in excess to ensure complete consumption of the other reactant. | Excess Use Strategy |
| Why is it common to deliberately use one of the reactants in excess in a reaction with 2 reactants? | Using one reactant in excess ensures that all of the other reactant will definitely get used up, optimizing the reaction yield. |
| The study and calculation of the quantitative relationships in chemical reactions, including the ratios of reactants and products. | Stoichiometry |
| What does the stoichiometry of a chemical reaction refer to? | The stoichiometry of a reaction refers to the ratios of the amounts of the different reactants and products. |
| The process of adjusting coefficients in a chemical equation to ensure the conservation of mass and atoms on both sides of the reaction. | Balancing Chemical Equations |
| What does it mean to balance a chemical equation? | Balancing a chemical equation involves adjusting coefficients to ensure the conservation of mass and atoms on both sides of the reaction. |
| The use of mole ratios to describe the quantitative relationships between reactants and products in a balanced chemical equation. | Moles in Chemical Equations |
| How are chemical equations described in terms of moles? | Chemical equations can be described in terms of moles, with the multipliers in front of the chemical formulae indicating the number of moles. If there's no multiplier, the number of moles is assumed to be 1. |
| For example, this equation shows that 1 mole of hydrogen reacts with 1 mole of chlorine to produce 2 moles of hydrochloric acid: | Example Balanced Equation |
| Moles can be used to balance equations. | Moles in Equation Balancing Introduction |
| You can write a balanced equation for a reaction if you know the masses of the reactants and products. For example, 27 g of aluminium reacts with 108 g of iron(II) oxide to form 51 g of aluminium oxide and 84 g of iron | Equation Writing Introduction |
| First, write an unbalanced equation by simply listing the formulae of the reactants on the left and products on the right. | Unbalanced Equation Writing - Step 1 |
| Use the masses of each reactant and product to calculate their amounts in moles. | Moles Calculation from Masses - Step 2 |
| In some cases, doubling the amounts in moles can yield whole number amounts, which can simplify balancing. | Moles Doubling for Whole Numbers - Step 3 |
| Moles show the proportions of reactants and products needed for a balanced equation, often written as multipliers before each molecular formula. | Moles Proportional Relationships - Step 4 |
| A balanced equation showing that 2 moles of aluminium react with 3 moles of iron(II) oxide to produce 1 mole of aluminium oxide. | Balanced Equation Example |
