Chapter 2 Study Guide - Tagged.pdf

Chapter 2 I. Atoms, Ions, and Molecules: The Building Blocks of Chemical Evolution A. Four atoms make up 96 percent of every organism. What are they? 1. 2. 3. 4. B. Basic atomic structure. Describe the structure of the atom. Drawings with labels are...

Chapter 2 I. Atoms, Ions, and Molecules: The Building Blocks of Chemical Evolution A. Four atoms make up 96 percent of every organism. What are they? 1. 2. 3. 4. B. Basic atomic structure. Describe the structure of the atom. Drawings with labels are acceptable. C. How does covalent bonding hold molecules together? D. Ionic bonding, ions, and the electron-sharing continuum. Explain ions and ionic bonding. E. Some simple molecules formed from C, H, N, and O. Study these structures. (it helps to draw them) a. Methane—CH4 (single bonds) b. Ammonia—NH3 (single bonds) c. Water—H2O (single bonds) d. CO2 (double bonds) e. N2 (triple bonds) F. The geometry of simple molecules. Draw the structure of the molecules in bold. 1. CO2 and N2 are linear. 2. Methane (CH4) is tetrahedral  3. Water (H2O) is a bent two-dimensional structure. II. Properties of Water and the Early Oceans A. Life is based on water. Study 1. Life arose in an aqueous environment. 2. Every cell is approximately 75 percent water (volume), making it the most abundant molecule in living organisms. 3. Humans can survive weeks without eating, but only three to four days without drinking water. B. Water is an efficient solvent—an agent for dissolving substances into a solution. Describe why this is the case. C. What properties are correlated with water’s structure? D. Explain the role of water in acid–base reactions III. Chemical Reactions, Energy, and Chemical Evolution A. Explain the theory of chemical evolution B. How do chemical reactions happen? C. What is energy? D. What makes chemical reactions spontaneous?  IV. Investigating Chemical Evolution A. What is the chemical evolution? B. Early origin-of-life experiments. Review the experiments. V. Life Is Carbon-Based A. Carbon atoms provide the structural framework for important compounds for life (excluding water), organic compounds. How are carbons linked? (what structures are formed) B. Functional groups. What are they and what are they special? More Chapter 2 Questions 1) A covalent chemical bond is one in which ________. A) electrons are removed from one atom and transferred to another atom so that the two atoms become oppositely charged B) protons and neutrons are shared by two atoms so as to satisfy the requirements of both atoms C) outer-shell electrons of two atoms are shared so as to satisfactorily fill their respective orbitals D) outer-shell electrons of one atom are transferred to fill the inner electron shell of another atom E) electrons from the same atom, but opposite spins, are paired 2) What is the difference between covalent bonds and ionic bonds? A) Covalent bonds require carbon whereas ionic bonds do not. B) Covalent bonds involve the sharing of pairs of electrons between atoms; ionic bonds involve the sharing of single electrons between atoms. C) Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the electrical attraction between charged atoms. D) Covalent bonds involve the sharing of electrons between atoms; ionic bonds involve the sharing of protons between charged atoms. E) Covalent bonds involve the transfer of electrons between charged atoms; ionic bonds involve the sharing of electrons between atoms. 3) What results from the chemical reaction illustrated above? The reactants have no charge. A) A cation with a net charge of +1 and an anion with a net charge of +1 B) A cation with a net charge of −1 and an anion with a net charge of −1 C) A cation with a net charge of −1 and an anion with a net charge of +1 D) A cation with a net charge of +1 and an anion with a net charge of −1 4) When the atoms involved in a covalent bond have the same electronegativity, what type of bond results? A) An ionic bond B) A hydrogen bond C) A nonpolar covalent bond D) A polar covalent bond 5) A solution with a pH of 5 has how many more protons in it than a solution with a pH of 7? A) 5 times B) 10 times C) 100 times D) 1000 times 6) Which type of bond must be broken for water to vaporize? A) Ionic bonds B) Both hydrogen bonds and ionic bonds C) Polar covalent bonds D) Hydrogen bonds E) Both polar covalent bonds and hydrogen bonds 7) Which of the following correctly describes all chemical equilibrium? A) Forward and reverse reactions continue with no net effect on the concentrations of the reactants and products. B) Concentrations of products are higher than the concentrations of the reactants. C) There are equal concentrations of products and reactants while forward and reverse reactions continue. D) Reactions stop only when all reactants have been converted to products. E) There are equal concentrations of reactants and products, and the reactions have stopped. 8) Which of the following always tends to make chemical reactions spontaneous? A) The reactants have lower potential energy than the products. B) The reactants are more ordered than the products. C) The temperature is low. D) The pressure is low. 9) Choose the correct sequence of numbers to fill in the blanks to balance this equation. A) 1, 2, 2 B) 1, 3, 2 C) 1, 3, 1 D) 1, 1, -1 Evaluate this chemical equation. Answer "True" or "False" for each of the following statements. 10) The equation is balanced. 11) The arrow indicates that the atoms of the reactants bond in new ways to form products. 12) The arrow indicates that the reaction is reversible. 13) There are the same number of hydrogen atoms (H) in the reactants as in the products. 14) H2O is a product. 15) There are the same number of carbon atoms (C) in the reactants as in the products.