Stoichiometry and Atomic Mass Concepts
16 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to Lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

Which of the following represents a positive charge ion in ionic compounds?

  • NO3-
  • Fe3+ (correct)
  • O2-
  • CO32-

    • The empirical formula of a compound represents the exact number of atoms of each element in a molecule.

    False (B)

    What is produced when zinc reacts with hydrochloric acid?

    zinc(II) chloride and hydrogen

    The _____ ion has the formula NH4+.

    <p>ammonium</p> Signup and view all the answers

    Match the following metals with their ions:

    <p>Zinc = Zn2+ Copper(I) = Cu+ Calcium = Ca2+ Aluminum = Al3+</p> Signup and view all the answers

    What is the relative atomic mass (Ar) based on?

    <p>The mass of an element compared to 1/12th of the mass of a carbon atom (A)</p> Signup and view all the answers

    A sulfate ion has the chemical formula SO4²-.

    <p>True (A)</p> Signup and view all the answers

    Relative molecular mass (Mr) is the sum of relative atomic masses of _____ compounds.

    <p>covalent</p> Signup and view all the answers

    What is Avogadro's constant?

    <p>6.02 x 10^23 particles (C)</p> Signup and view all the answers

    1 mole of any gas occupies 22 dm3 at room temperature.

    <p>False (B)</p> Signup and view all the answers

    What is the empirical formula of sulfur oxide formed from 32g of sulfur and 32g of oxygen?

    <p>SO2</p> Signup and view all the answers

    The formula to calculate moles is n = mass / __________.

    <p>Mr</p> Signup and view all the answers

    If 2.4g of magnesium reacts with excess dilute hydrochloric acid, what is the volume of hydrogen gas produced?

    <p>2.4 dm3 (B)</p> Signup and view all the answers

    The percentage yield is the ratio of actual yield to theoretical yield expressed as a percentage.

    <p>True (A)</p> Signup and view all the answers

    For magnesium reacting with hydrochloric acid, the ratio of Mg to H2 is __________.

    <p>1:1</p> Signup and view all the answers

    Match the following calculations to their respective outcomes:

    <p>Calculate moles of Mg = 0.1 moles Volume of gas from moles = 2.4 dm3 Mass of NaCl in moles = 58.5 g Volume occupied by 1 mole of gas = 24 dm3</p> Signup and view all the answers

    Flashcards

    Metal Ions

    Positively charged ions formed when metal atoms lose electrons.

    Nonmetal Ions

    Negatively charged ions formed when nonmetal atoms gain electrons.

    Empirical Formula

    The simplest whole number ratio of different atoms/ions in a compound.

    Molecular Formula

    The number and type of different atoms in one molecule.

    Signup and view all the flashcards

    Relative Atomic Mass (Ar)

    The average mass of isotopes of an element compared to 1/12th of the mass of carbon atom.

    Signup and view all the flashcards

    Relative Molecular Mass (Mr)

    The sum of relative atomic masses of all atoms in a covalent compound.

    Signup and view all the flashcards

    Relative Formula Mass (Mr)

    The sum of relative atomic masses of all atoms in an ionic compound.

    Signup and view all the flashcards

    Reacting Mass Calculations

    Calculations involving the masses of reactants and products in a chemical reaction.

    Signup and view all the flashcards

    What is a mole?

    The mole (mol) is the SI unit for amount of substance. It represents a specific number of particles, which is Avogadro's constant: 6.02 x 10^23 particles per mole.

    Signup and view all the flashcards

    What is Avogadro's Constant?

    Avogadro's constant (NA) is the number of particles (atoms, molecules, ions, etc.) in one mole of a substance. It's approximately 6.02 x 10^23 particles per mole.

    Signup and view all the flashcards

    What is molar mass?

    The molar mass (Mr) of a substance is the mass of one mole of that substance, expressed in grams per mole (g/mol).

    Signup and view all the flashcards

    What is the molar volume of a gas at STP?

    At standard temperature and pressure (STP), one mole of any ideal gas occupies a volume of 24 dm3 (24 liters).

    Signup and view all the flashcards

    What is an empirical formula?

    The empirical formula of a compound shows the simplest whole-number ratio of atoms of each element present in the compound.

    Signup and view all the flashcards

    What is percentage yield?

    The percentage yield is the actual yield of a reaction divided by the theoretical yield, multiplied by 100%. It indicates the efficiency of the reaction.

    Signup and view all the flashcards

    What is theoretical yield?

    The theoretical yield is the maximum amount of product that could be produced from a given amount of reactants, assuming 100% efficiency.

    Signup and view all the flashcards

    What is actual yield?

    The actual yield is the amount of product that is actually produced in a chemical reaction. It may be less than the theoretical yield due to inefficiencies or side reactions.

    Signup and view all the flashcards

    Study Notes

    Stoichiometry

    • Stoichiometry is the calculation of reactants and products in a chemical reaction.
    • Formulae of elements and compounds must be known.
    • Molecular formula: the number and type of atoms in a molecule.
    • Empirical formula: simplest whole number ratio of elements in a compound.
    • Simple compound formula can be derived from models or diagrams.
    • Word and symbol equations show reactant-product transformations, including state symbols.
    • Ionic compound formulae are derived from the relative number of ions, and their charges.
    • Polyatomic ions are groups of atoms that behave as a single unit, for example: carbonate (CO₃²⁻), nitrate (NO₃⁻), ammonium (NH₄⁺), hydroxide (OH⁻), and sulfate (SO₄²⁻).
    • Examples of metals: Group 1 (K⁺, Na⁺), Group 2 (Ca²⁺, Mg²⁺), Group 3 (Al³⁺), Transition metals (Zn²⁺, Cu⁺, Cu²⁺, Ag⁺, Fe²⁺, Fe³⁺, Cr³⁺).

    Relative Masses of Atoms and Molecules

    • Relative atomic mass (Ar) is the average mass of isotopes compared to ¹/₁₂ of ¹²C.
    • Relative molecular mass (Mr) of covalent compounds is the sum of relative atomic masses.
    • Relative formula mass (Mr) of ionic compounds is the sum of relative atomic masses.
    • Calculating reacting masses involves simple proportions, without moles.

    The Mole and Avogadro Constant

    • The mole (mol) is the unit of amount of substance.
    • One mole contains 6.02 x 1023 particles (Avogadro constant).
    • Amount of substance (mol) = mass (g) / molar mass (g/mol)
    • Calculations can find molar mass, amount of substance, masses, and the number of particles.
    • Molar gas volume of a gas under room temperature and pressure is 24 dm³.

    Gas Calculations

    • 1 mole of any gas occupies 24 dm³ at room temperature and pressure (r.t.p. = 25°C, 1 atm).
    • Gas volume calculations involve stoichiometry.

    Percentage Yield

    • Percentage yield is the ratio of the actual mass obtained to the theoretical mass, multiplied by 100%.
    • Actual yield is the mass of a product obtained in a chemical reaction.
    • Theoretical yield is the maximum mass of product that could be produced.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Stoichiometry PDF

    Description

    This quiz covers the essential concepts of stoichiometry, including the calculation of reactants and products in chemical reactions. You will explore molecular and empirical formulas, the role of ionic compounds, and the fundamentals of relative atomic mass. Test your knowledge and understanding of these core topics in chemistry.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser