Describe the secondary structure of the protein collagen.
> For Exercises 55–76 choose one of the following terms to match the description given. a. aldohexose b. antibody c. cellulose d. CH2O e. cysteine f. denaturation g. disaccharides h. disulfide i. DNA j. enzymes k. fibrous l. globular m. glycog
> Using the ions indicated in Problem 24, write the formulas and give the names for all possible simple ionic compounds involving these ions. From problem 24: a. Mg2+ b. Fe2+ c. Fe3+ d. F- e. Ni2+ f. Zn2+ g. Co3+ h. N3- i. S2- j. Rb+ k. Se2- l.
> For Exercises 55–76 choose one of the following terms to match the description given. a. aldohexose b. antibody c. cellulose d. CH2O e. cysteine f. denaturation g. disaccharides h. disulfide i. DNA j. enzymes k. fibrous l. globular m. glycog
> For Exercises 55–76 choose one of the following terms to match the description given. a. aldohexose b. antibody c. cellulose d. CH2O e. cysteine f. denaturation g. disaccharides h. disulfide i. DNA j. enzymes k. fibrous l. globular m. glycog
> For Exercises 55–76 choose one of the following terms to match the description given. a. aldohexose b. antibody c. cellulose d. CH2O e. cysteine f. denaturation g. disaccharides h. disulfide i. DNA j. enzymes k. fibrous l. globular m. glycog
> For Exercises 55–76 choose one of the following terms to match the description given. a. aldohexose b. antibody c. cellulose d. CH2O e. cysteine f. denaturation g. disaccharides h. disulfide i. DNA j. enzymes k. fibrous l. globular m. glycog
> What are bile acids, and from what are they synthesized by the body? What is the most common bile acid, and what function does it serve?
> Choose 10 species that might be expected to behave as Brønsted–Lowry acids or bases in aqueous solution. For each of your choices, (a) write an equation demonstrating how the species behaves as an acid or base in water, and (b) write the formula of the
> What types of hormones are synthesized in the adrenal glands and are involved in various regulatory functions in the body? Provide an example of this type of hormone.
> What is a steroid? What basic ring structure is common to all steroids? Sketch an example of a steroid found in the body, and highlight the basic ring structure that makes the molecule a steroid.
> Write the electron configuration for the following atoms, using the appropriate noble gas to abbreviate the configuration of the core electrons. a. Sr, Z = 38 b. Al, Z = 13 c. Cl, Z = 17 d. K, Z = 19 e. S, Z = 16 f. As, Z = 33
> Which are the valence electrons in an atom? Choose three elements and write their electron configurations, circling the valence electrons in the configurations. Why are the valence electrons more important to an atom’s chemical properties than are the co
> Chapter 2 introduced the Kelvin and Celsius temperature scales and related them to the Fahrenheit temperature scale commonly used in the United States. a. How is the size of the temperature unit (degree) related between the Kelvin and Celsius scale? b.
> Methane, CH4, is the major component of natural gas. Methane burns in air, releasing approximately 890 kJ of heat energy per mole. CH4(g) + 2O2(g) CO2(g) + 2H2O(g) a. What quantity of heat is released if 0.521 mole of methane is burned?
> Which of the following statements is correct and provides the best explanation when removing the first two electrons from calcium? a. Energy is released when either electron comes off because calcium is a metal and not very electronegative. b. It takes
> Sketch the general structure of a triglyceride. What are the components that go into making up a typical triglyceride?
> What are the four classes of lipids? Give an example of a member of each class.
> Lipids are a group of substances defined in terms of their characteristics.
> What is a gene?
> A traditional analysis for samples containing calcium ion was to precipitate the calcium ion with sodium oxalate (Na2C2O4) solution and then to collect and weigh either the calcium oxalate itself or the calcium oxide produced by heating the oxalate preci
> Write formulas for each of the following compounds. a. mercuric chloride b. iron(III) oxide c. sulfurous acid d. calcium hydride e. potassium nitrate f. aluminum fluoride g. dinitrogen monoxide h. sulfuric acid i. potassium nitride j. nitrogen d
> Name the five nitrogen bases found in DNA and RNA. Which base is found commonly in RNA but not in DNA? Which base is found commonly in DNA but not in RNA?
> DNA nucleotides contain the pentose , whereas RNA nucleotides contain the pentose .
> For each of the following, make the indicated conversion. a. 4,861,903 to standard scientific notation b. 3.8136 * 102 to ordinary decimal notation c. 5.1 * 10-3 to ordinary decimal notation d. 0.000744 to standard scientific notation e. 8.621 * 105
> RNA molecules, which are found in the cytoplasm outside the cell nucleus, are much (smaller/larger) than DNA polymers.
> carries the information needed for the synthesis of the various proteins the cell requires to carry out its life functions.
> In addition to using numerical prefixes in the general names of sugars to indicate how many carbon atoms are present, we often use the prefixes keto- and aldo- to indicate whether the sugar is a ketone or an aldehyde. For example, the monosaccharide fruc
> Sketch a representation of the disaccharide sucrose (table sugar). Label clearly the portion of the disaccharide that originates from glucose, the portion that originates from fructose, and the glycoside linkage between the rings.
> Give the name of each of the following compounds. a. XeO2 b. ICl5 c. PCl3 d. CO e. OF2 f. P2O5 g. AsI3 h. SO3
> What is a disaccharide? What monosaccharide units make up the disaccharide sucrose? What is the bond called that forms between the monosaccharide units?
> What is a hexose sugar? Sketch the straight-chain representation of the hexose galactose.
> Sketch the ring structures of glucose and fructose. Based on the electron pairs surrounding the atoms of the rings, would you expect these rings to be planar (flat)?
> Many of the most important carbohydrates are , which are large molecules constructed by hooking together many smaller molecules.
> Consider the reaction as represented by the following unbalanced chemical equation: 2H2(g) + O2(g) ( 2H2O(g) You react 15.0 g of hydrogen gas with 100.0 g of oxygen gas. Determine the amount of reactant in excess (in grams) after the reaction is comp
> Most people think of science as being a specific, exact discipline, with a “correct” answer for every problem. Yet you were introduced to the concept of uncertainty in scientific measurements. What is meant by “uncertainty”? How does uncertainty creep in
> Calculate the percent by mass of the element whose symbol occurs first in the following compounds’ formulas. a. C6H6(l) b. Na2SO4(s) c. CS2(l) d. AlCl3(s) e. Cu2O(s) f. CuO(s) g. Co2O3(s) h. C6H12O6(s)
> What name is given to the specific portion of the enzyme molecule where catalysis actually occurs?
> Write the formula for each of the following binary ionic compounds. a. copper(I) iodide b. cobaltous chloride c. silver sulfide d. mercurous bromide e. mercuric oxide f. chromium(III) sulfide g. plumbic oxide h. potassium nitride i. stannous fluo
> How does the efficiency of an enzyme compare with that of inorganic catalysts? Are enzymes more or less efficient?
> How are proteins able to act as buffering agents in the blood and tissues?
> What are antibodies? How do they work?
> What is the name of the protein found in all cells that extracts energy from food molecules by transferring electrons in a series of oxidation–reduction reactions??
> What name is given to proteins that catalyze biochemical reactions in the cell?
> What protein is responsible for the transport of oxygen through the bloodstream?
> Which of the following represent physical properties or changes, and which represent chemical properties or changes? a. You curl your hair with a curling iron. b. You curl your hair by getting a “permanent wave” at the hair salon. c. Ice on your sidew
> In Chapter 2 of this text, you were introduced to the International System (SI) of measurements. What are the basic units of this system for mass, distance, time, and temperature? What are some of the prefixes used to indicate common multiples and subdiv
> An S-S bond between two cysteine amino acids on a protein is called a(n) . This bond stabilizes the tertiary structure of many proteins.
> Complete the following table by giving the symbol, name, atomic number, and/or group(family) number as required. Atomic Group Symbol Name Number Number Ca I cesium 16 arsenic Sr 14 Rn radium Se ||
> Silk consists of a(n) structure in which the individual chains of amino acids are lined up lengthwise next to each other.
> Consider the neutron, the proton, and the electron. a. Which is(are) found in the nucleus? b. Which has the largest relative mass? c. Which has the smallest relative mass? d. Which is negatively charged? e. Which is electrically neutral?
> In general terms, what does the secondary structure of a protein represent?
> What does the primary structure of a protein rep resent? How are the individual units that make up the overall primary structure of a protein held together?
> What is a peptide linkage? Choose two amino acids from Fig. 21.2 and draw structures for the two dipeptides those amino acids are capable of forming, circling the peptide linkage in each. From figure 21.2 Answer: The “peptide linkage&
> How many unique amino acid sequences are possible for a tripeptide containing only the amino acids gly, ala, and cys, with each amino acid occurring only once in each molecule?
> Given the structures of the amino acids alanine and serine as shown in Fig. 21.2, draw structures for each of the two dipeptides that these amino acids might form. From figure 21.2
> Many college students would not choose to take a chemistry course if it were not required for their major. Do you have a better appreciation of why chemistry is a required course for your own particular major or career choice? Discuss.
> Perhaps the most important concept in introductory chemistry concerns what a mole of a substance represents. The mole concept will come up again and again in later chapters in this book. What does one mole of a substance represent on a microscopic, atomi
> Given the structures of the amino acids in Fig. 21.2, choose two amino acids that you would expect to have hydrophobic side chains and two amino acids that you would expect to have hydrophilic side chains, and explain your choices in terms of the structu
> Nonpolar side chains in a-amino acids tend to be , whereas polar side chains are most often in an aqueous medium.
> The symbols for the elements silver (Ag), gold (Au), and tungsten (W) seem to bear no relation to their English names. Explain and give three additional examples.
> Without consulting any reference, write the name and symbol for as many elements as you can. How many could you name? How many symbols did you write correctly?
> What is an element? Which elements are most abundant on the earth? Which elements are most abundant in the human body?
> What are proteins? Are proteins polymers? Explain. What molar mass ranges are shown by proteins? What fraction of our bodies is made up of proteins?
> What are trace elements, and why are such elements important to the body’s health?
> is the study of the chemistry of living systems.
> Complete and balance the following equations. a. Pb(NO3)2(aq) + Na2S(aq) / b. AgNO3(aq) + HCl(aq) / c. 2Mg(s) + O2(g) / d. H2SO4(aq) + 2KOH(aq) / e. BaCl2(aq) + H2SO4(aq) / f. Mg(s) + H2SO4(aq) / g. 2Na3PO3(aq) + 3CaCl2(aq) / h. 2C4H10(l) + 13O2(g) /
> Write the balanced net ionic equation for the reaction that takes place when aqueous solutions of the following solutes are mixed. If no reaction is likely, explain why no reaction would be expected for that combination of solutes. a. potassium nitrate
> What is meant by denaturation of a protein? Give three examples of situations in which proteins are denatured.
> Give balanced equations for two examples of each of the following types of reactions. a. precipitation b. single-displacement c. combustion d. synthesis e. oxidation – reduction f. decomposition g. acid–base neutralization
> Balance each equation. Which equations can be classified as oxidation–reduction reactions? a. FeO(s) + HNO3(aq) Fe(NO3)2(aq) + H2O(l) b. Mg(s) + CO2(g) + O2(g) MgCO3(s) c. NaOH(s) + CuSO4(aq) Cu(OH)2(s) + N
> The reagent shelf in a general chemistry lab contains aqueous solutions of the following substances: silver nitrate, sodium chloride, acetic acid, nitric acid, sulfuric acid, potassium chromate, barium nitrate, phosphoric acid, hydrochloric acid, lead ni
> Balance each of the following chemical equations. a. Na2SO4(aq) + BaCl2(aq) BaSO4(s) + NaCl(aq) b. Zn(s) + H2O(g) ZnO(s) + H2(g) c. NaOH(aq) + H3PO4(aq) Na3PO4(aq) + H2O(l) d. Al(s) + Mn2O3(s)
> List and define all the ways of classifying chemical reactions that have been discussed in the text. Give a balanced chemical equation as an example of each type of reaction, and show clearly how your example fits the definition you have given.
> Give an example of a synthesis reaction and of a decomposition reaction. Are synthesis and decomposition reactions always also oxidation–reduction reactions? Explain.
> What is a combustion reaction? Are combustion reactions a unique type of reaction, or are they a special case of a more general type of reaction? Write an equation that illustrates a combustion reaction.
> What do we call reactions in which electrons are transferred between atoms or ions? What do we call a loss of electrons by an atom or ion? What is it called when an atom or ion gains electrons? Can we have a process in which electrons are lost by one spe
> What is a salt? How are salts formed by acid–base reactions? Write chemical equations showing the formation of three different salts. What other product is formed when an aqueous acid reacts with an aqueous base? Write the net ionic equation for the form
> Describe some physical and chemical properties of acids and bases. What is meant by a strong acid or base? Are strong acids and bases also strong electrolytes? Give several examples of strong acids and strong bases.
> a. Given that 100. mL of ethyl alcohol weighs 78.5 g, calculate the density of ethyl alcohol. b. What volume would 1.59 kg of ethyl alcohol occupy? c. What is the mass of 1.35 L of ethyl alcohol? d. Pure aluminum metal has a density of 2.70 g/cm3. Cal
> In general terms, what are the spectator ions in a precipitation reaction? Why are the spectator ions not included in writing the net ionic equation for a precipitation reaction? Does this mean that the spectator ions do not have to be present in the sol
> Summarize the simple solubility rules for ionic compounds. How do we use these rules in determining the identity of the solid formed in a precipitation reaction? Give examples including balanced complete and net ionic equations.
> Define the term strong electrolyte. What types of substances tend to be strong electrolytes? What does a solution of a strong electrolyte contain? Give a way to determine if a substance is a strong electrolyte.
> Explain to your friend what chemists mean by a precipitation reaction. What is the driving force in a precipitation reaction? Using the information provided about solubility in these chapters, write balanced molecular and net ionic equations for five exa
> What is meant by the driving force for a reaction? Give some examples of driving forces that make reactants tend to form products. Write a balanced chemical equation illustrating each type of driving force you have named.
> When balancing a chemical equation, why is it not permissible to adjust the subscripts in the formulas of the reactants and products? What would changing the subscripts within a formula do? What do the coefficients in a balanced chemical equation represe
> What does it mean to “balance” an equation? Why is it so important that equations be balanced? What does it mean to say that atoms must be conserved in a balanced chemical equation? How are the physical states of reactants and products indicated when wri
> What, in general terms, does a chemical equation indicate? What are the substances indicated to the left of the arrow called in a chemical equation? To the right of the arrow?
> What kind of visual evidence indicates that a chemical reaction has occurred? Give an example of each type of evidence you have mentioned. Do all reactions produce visual evidence that they have taken place?
> a. Fill in the following table as if it is a well plate and you are mixing two aqueous compounds at a time to see if a precipitate forms. If a precipitate is expected to form, indicate that by writing the correct formula for the precipitate in the corres
> In general terms, what does the tertiary structure of a protein describe? Clearly distinguish between the secondary and tertiary structures.
> Which of the following solutions contains the greatest number of ions? a. 100.0 mL of 1.0 M sodium nitrate b. 100.0 mL of 1.0 M iron(III) nitrate c. 100.0 mL of 1.0 M copper(II) nitrate d. 100.0 mL of 1.0 M calcium nitrate e. All of the solutions ab
> In an open flask, 20.0 mL of an aqueous solution (density of solution = 1.103 g/mL) is combined with 13.5 g of a solid, and a chemical reaction takes place. One of the reaction products is 1.473 L of gas with density 5 1.798 g/L. What is the mass of the
> Rank the following species from lowest to highest boiling point: N2(l), Ne(l), BeO(l), CO(l)
> If 125 mL of concentrated sulfuric acid solution (density 1.84 g/mL, 98.3% H2SO4 by mass) is diluted to a final volume of 3.01 L, calculate the following information. a. the mass of pure H2SO4 in the 125-mL sample. b. the molarity of the concentrated a
> Calculate the volume (in milliliters) of each of the following acid solutions that would be required to neutralize 36.2 mL of 0.259 M NaOH solution. a. 0.271 M HCl b. 0.119 M H2SO4 c. 0.171 M H3PO4
> Chlorine gas, Cl2, can be generated in small quantities by addition of concentrated hydrochloric acid to manganese(IV) oxide. MnO2(s) + 4HCl(aq) / MnCl2(aq) + 2H2O(l) + Cl2(g) The chlorine gas is bubbled through water to dissolve any traces of HCl remai
> Calculate the indicated quantity for each gas sample. a. The volume occupied by 1.15 g of helium gas at 25 °C and 1.01 atm pressure. b. The partial pressure of each gas if 2.27 g of H2 and 1.03 g of He are confined to a 5.00-L container at 0 °C. c. Th
> What is one equivalent of an acid? What does an equivalent of a base represent? How is the equivalent weight of an acid or a base related to the substance’s molar mass? Give an example of an acid and a base that have equivalent weights equal to their mol
> When a solution is diluted by adding additional solvent, the concentration of solute changes but the amount of solute present does not change. Explain. Suppose 250. mL of water is added to 125 mL of 0.551 M NaCl solution. Explain how you would calculate
> Define a saturated solution. Does saturated mean the same thing as saying the solution is concentrated? Explain. Why does a solute dissolve only to a particular extent in water? How does formation of a saturated solution represent an equilibrium?
