Chemistry: Dalton's Atomic Theory and Bonds
29 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

What is the key characteristic of atoms according to Dalton's atomic theory?

  • Atoms are always visible to the naked eye.
  • Atoms of one element are all identical. (correct)
  • Atoms can be divided into smaller particles.
  • Atoms can change into different elements.

What type of bond typically occurs between a metal and a non-metal?

  • Hydrogen Bond
  • Covalent Bond
  • Polar Covalent Bond
  • Ionic Bond (correct)

What is the range of electronegativity difference that indicates a polar covalent bond?

  • 0.5 to 1.6 (correct)
  • 0.0 to 0.4
  • ≥ 2.6
  • 1.7 to 2.5

According to Dalton, what forms when atoms combine?

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

In terms of polarity, what signifies the distribution of electric charge among atoms in a bond?

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

What molecular shape is characterized by a central atom with two bonded atoms and two lone pairs?

<p>Bent (C)</p> Signup and view all the answers

Which of the following compounds exhibits a tetrahedral molecular shape?

<p>Methane (CH4) (C)</p> Signup and view all the answers

What type of bond is formed when electrons are shared unequally between atoms?

<p>Polar covalent bond (A)</p> Signup and view all the answers

Which molecular shape features three bonded atoms arranged in a triangle around a central atom?

<p>Trigonal (D)</p> Signup and view all the answers

Identify the molecular shape that consists of four bonded atoms arranged in a flat square.

<p>Square planar (C)</p> Signup and view all the answers

What is the bond angle in a tetrahedral molecular structure?

<p>109.5° (A)</p> Signup and view all the answers

Which molecule is an example of a pyramidal molecular shape?

<p>Pnictogen hydrides (XH3) (C)</p> Signup and view all the answers

Which of the following best describes electronegativity?

<p>The relative tendency of an atom to attract electrons (C)</p> Signup and view all the answers

What effect do lone pairs have on bond angles in molecular structures?

<p>They decrease bond angles slightly. (D)</p> Signup and view all the answers

Which of the following molecules is an example of a polar molecule?

<p>PCI3 (A), OCF2 (B)</p> Signup and view all the answers

What is the definition of solubility?

<p>The ability of a solid substance to dissolve in a solvent. (A)</p> Signup and view all the answers

What does the phrase 'like dissolves like' imply?

<p>Polar solvents can only dissolve polar solutes. (A)</p> Signup and view all the answers

What characterizes polar bonds in a molecule?

<p>Unequal sharing of electrons due to electronegativity differences. (C)</p> Signup and view all the answers

Which of the following statements is true regarding miscibility?

<p>Miscibility refers to the ability of two liquids to mix in all proportions. (A)</p> Signup and view all the answers

Which molecular structure is primarily characterized by having tetrahedral bond angles?

<p>CCl4 (D)</p> Signup and view all the answers

What type of charge separation indicates a molecule is polar?

<p>Presence of an electric dipole moment. (C)</p> Signup and view all the answers

Which pairs of substances are likely to mix due to their polarity?

<p>benzene (C6H6) and chloroform (CHCl3) (B), water (H2O) and vinegar (CH3COOH) (C)</p> Signup and view all the answers

Which of the following statements about intermolecular forces of attraction (IMFA) is true?

<p>Stronger IMFA leads to higher viscosity. (C)</p> Signup and view all the answers

Which of the following correctly pairs a physical property with its definition?

<p>Viscosity: the resistance of a liquid to flow. (A)</p> Signup and view all the answers

Which substances are nonpolar and would likely not mix with polar substances?

<p>benzene (C6H6) (C), carbon tetrachloride (CCl4) (D)</p> Signup and view all the answers

Which property generally decreases as the strength of intermolecular forces increases?

<p>Vapor pressure (C)</p> Signup and view all the answers

What happens to viscosity when intermolecular forces are weakened?

<p>Viscosity decreases. (D)</p> Signup and view all the answers

Which of the following mixtures would be expected to have the highest boiling point?

<p>water (H2O) and vinegar (CH3COOH) (C)</p> Signup and view all the answers

What defines the vapor pressure of a substance?

<p>Pressure exerted by a substance in its gaseous state. (A)</p> Signup and view all the answers

Flashcards

Atomic Theory

Dalton's theory proposes that atoms are tiny, indivisible particles that differ in elements.

Ionic Bond

A bond formed when a metal loses electrons and a nonmetal accepts those electrons.

Covalent Bond

A bond formed when atoms share electron pairs.

Electronegativity

Measure of the tendency for an atom to attract electrons in a bond.

Signup and view all the flashcards

Polarity of a molecule

Distribution of electric charge among atoms in a bond.

Signup and view all the flashcards

Polar Covalent Bond

A chemical bond where electrons are shared unequally between atoms, creating an electric dipole.

Signup and view all the flashcards

Bent Molecular Shape

A molecular shape where the central atom has lone pairs, pushing bonded atoms into a "V" shape.

Signup and view all the flashcards

Tetrahedral Shape

A symmetrical three-dimensional shape with four atoms evenly spaced around a central atom.

Signup and view all the flashcards

Trigonal Molecular Shape

A flat, triangular shape with three bonded atoms around a central atom.

Signup and view all the flashcards

Pyramidal Molecular Shape

A three-dimensional shape with three bonded atoms forming a triangle and a lone pair on the central atom.

Signup and view all the flashcards

Square Planar Shape

A flat, square shape with four atoms around a central atom, often influenced by lone pairs or electron repulsion.

Signup and view all the flashcards

VSEPR Theory

Valence Shell Electron Pair Repulsion theory describing the shapes of molecules based on electron pair repulsion.

Signup and view all the flashcards

Lone Pair Repulsion

The repulsion between lone pairs of electrons on a central atom, which causes bond angles in molecules to be slightly less than the ideal tetrahedral angle of 109.5 degrees.

Signup and view all the flashcards

Xenon Tetrafluoride (XeF4)

A molecule with a square planar shape, where the central xenon atom is surrounded by four fluorine atoms and two lone pairs, resulting in bond angles close to 90 degrees.

Signup and view all the flashcards

Polar Molecule

A molecule with a separation of electric charge, creating a positive and a negative end due to an uneven distribution of electrons.

Signup and view all the flashcards

Non-Polar Molecule

A molecule with an even distribution of electric charge, where electrons are shared equally between atoms.

Signup and view all the flashcards

Solubility

The ability of a solid substance to dissolve in a given amount of solvent.

Signup and view all the flashcards

Miscibility

The ability of two liquids to mix completely in all proportions, forming a homogenous mixture.

Signup and view all the flashcards

Like Dissolves Like

A principle stating that polar substances tend to dissolve in polar solvents, while non-polar substances dissolve in non-polar solvents.

Signup and view all the flashcards

Polarity and Solubility

The polarity of a molecule determines its solubility. Polar molecules are soluble in polar solvents, and non-polar molecules are soluble in non-polar solvents.

Signup and view all the flashcards

Polar & Non-Polar Mixtures

Polar substances only mix with other polar substances, while non-polar substances mix with other non-polar substances. This is the 'like dissolves like' rule.

Signup and view all the flashcards

Intermolecular Forces (IMFA)

The attractions between molecules, which influence a substance's physical properties like boiling point and viscosity.

Signup and view all the flashcards

Stronger IMFA = ?

Stronger intermolecular forces lead to higher boiling point, melting point, viscosity and surface tension, but lower vapor pressure and volatility.

Signup and view all the flashcards

Vapor Pressure

The pressure exerted by a substance in its gaseous state.

Signup and view all the flashcards

Boiling Point

The temperature at which the vapor pressure of a liquid equals the atmospheric pressure, causing the liquid to change into a gas.

Signup and view all the flashcards

Study Notes

John Dalton's Atomic Theory

  • Dalton (1808) created the first atomic theory
  • He conducted experiments on atoms
  • Dalton viewed atoms as tiny, solid spheres

Dalton's Atomic Theory Statements

  • Atoms are tiny and indivisible particles
  • Atoms of the same element are identical
  • Atoms of different elements are different
  • Compounds are formed by combining atoms

Types of Chemical Bonds

  • Ionic Bonds: Occur between metals and nonmetals
    • Metal loses electrons, nonmetal gains electrons
  • Covalent Bonds: Occur between nonmetals
    • Electrons are shared between atoms

Bond Polarity

  • Electronegativity difference determines bond polarity
    • High difference (≥ 1.7): Ionic bond
    • Moderate difference (0.5 to 1.6): Polar covalent bond
    • Low difference (< 0.4): Nonpolar covalent bond

Molecular Shapes

  • Linear: Atoms arranged in a straight line (180°)
  • Bent: Atoms arranged in a "V" shape (< 120° for example)
  • Trigonal planar: Atoms arranged in a flat triangle (120°)
  • Tetrahedral: Atoms arranged in a three-dimensional pyramid shape (approximately 109.5°)
  • Square planar: Atoms in a flat square around the central atom (90°)

Molecular Polarity

  • Polar molecules have opposite charges on different parts of the molecule.
  • Nonpolar molecules have even charge distribution

Examples of Molecular Shapes

  • Linear: CO2, BeCl2
  • Bent: H2O, NO2
  • Trigonal planar: BF3, NO3
  • Tetrahedral: CH4, NH4+
  • Square planar: XeF4

Examples of substances

  • Carbon dioxide (CO2)
  • Beryllium chloride (BeCl2)
  • Nitric oxide (NO)
  • Beryllium fluoride (BeF2)
  • Hydrogen cyanide (HCN)
  • Xenon difluoride (XeF2)
  • Methane (CH4)
  • Silane (SiH4)

Studying That Suits You

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

Quiz Team

Related Documents

Chemistry PDF - Atomic Theory, Bonds, and Polarity

Description

This quiz covers John Dalton's atomic theory, including its core statements and principles. Additionally, it explores different types of chemical bonds, their properties, and the concept of bond polarity. Test your understanding of atomic theory and molecular shapes!

More Like This

Use Quizgecko on...
Browser
Open
Browser
Browser