BIOL1414 Exam #1 (Ch1-7)
5.65. Copper(I) iodide (CuI) is often added to table salt as a dietary source of iodine. How many moles of CuI are contained in 1.00 lb (454 g) of table salt containing 0.0100% CuI by mass?
2.38×10^−4 mol
2.21. Explain at least three functions that lipids serve in plants and/or animals.
Insulation from the environment Long term storage of energy Building blocks of many hormones and are an important constituent of the plasma membrane
5.37. Consider this question: What is the mass of the solute in 0.500 L of 0.30 M glucose, C6H12O6, used for intravenous injection? (a) Outline the steps necessary to answer the question. (b) Answer the question.
Molarity (mol/L) = Number of Moles of solute/Volume of solution 0.30M (mol/L) = n mols/0.500L n = 0.500L x 0.30 mol/L = 0.15 mol C6H12O6 = (12•6)+(1•12)+(16*6) = 72+12+96=180g/mol Number of moles (n) = (Mass of solute Wg) / (Molar Mass g/mol) 0.15 mol = Wg/(180g/mol) Wg = 0.15 mol x 180g/mol = 27g
5.33. What information is needed to calculate the molarity of a sulfuric acid solution?
Molarity = number of moles/L Number of moles of sulfuric acid and the volume of solution is needed
5.11. How are the molecular mass and the molar mass of a compound similar and how are they different?
Molecular mass = mass of 1 molecule Molar mass = mass of 1 mol (6.022x10^23) of molecules
5.30. A tube of toothpaste contains 0.76 g of sodium monofluorophosphate (Na2PO3F) in 100 mL. (a) What mass of fluorine atoms in mg was present? (b) How many fluorine atoms were present?
Na2PO3F=(23•2)+31+(16•3)+19=144g/mol F=19g/mol (19g/mol)/(144g/mol) x 0.76g = 0.1003g = 100.3mg 0.1003g x 6.022x10^23 atoms/mol x 1 mol/19g = 0.032x10^23 atoms of F = 3.2x10^21 atoms of F
5.32. Explain what changes and what stays the same when 1.00 L of a solution of NaCl is diluted to 1.80 L.
Number of NaCl molecules stays the same Concentration and the volumes change
2.1. How many neutrons do (K) potassium-39 and potassium-40 have, respectively?
Potassium-39 has 20 neutrons and Potassium-40 has 21 neutrons
2.19. What would happen if no carbonic anhydrase were present in red blood cells?
Without carbonic anhydrase, carbon dioxide would not be hydrolyzed into carbonic acid or bicarbonate. Therefore, very little carbon dioxide (only 15 percent) would be transported in the blood away from the tissues.
3.7. What is the purpose and benefit of the polymerase chain reaction?
To rapidly replicate multiple copies of DNA from a limited quantity (small sample size)
2.18. Explain why water is an excellent solvent.
Water molecules are polar and allows it to form hydrogen bonds easily with certain solutes
5.59. What mass of solid NaOH (97.0% NaOH by mass) is required to prepare 1.00 L of a 10.0% solution of NaOH by mass? The density of the 10.0% solution is 1.109 g/mL.
114g
5.17. Determine the mass of each of the following: (a) 0.0146 mol KOH (b) 10.2 mol ethane, C2H6 (c) 1.6 10−3 mol Na2 SO4 (d) 6.854 103 mol glucose, C6 H12 O6 (e) 2.86 mol Co(NH3)6Cl3
(a) 0.0146 mol KOH KOH=39+16+1=56g/mol 56g/mol x 0.0146 mol = 0.8176g (b) 10.2 mol ethane, C2H6 C2H6=(12*2)+(1*6)=30g/mol 30g/mol x 10.2 mol = 306g (c) 1.6 10−3 mol Na2 SO4 (d) 6.854 103 mol glucose, C6 H12 O6 (e) 2.86 mol Co(NH3)6Cl3
5.35. Determine the molarity for each of the following solutions: (a) 0.444 mol of CoCl2 in 0.654 L of solution (b) 98.0 g of phosphoric acid, H3PO4, in 1.00 L of solution (c) 0.2074 g of calcium hydroxide, Ca(OH)2, in 40.00 mL of solution (d) 10.5 kg of Na2SO4 10H2O in 18.60 L of solution (e) 7.0 10−3 mol of I2 in 100.0 mL of solution (f) 1.8 104 mg of HCl in 0.075 L of solution
(a) 0.444 mol/0.654 L = 0.679 mol/L = 0.679M (b) H3PO4 = (1•3)+31+(16•4) = 98g/mol [98.0g/(98g/mol)]/L = 1 mol/L = 1M (c) Ca(OH)2 = 40+(16+1)•2 = 74g/mol [0.2074g/(74g/mol)]/0.040L = 0.07mol/L = 0.07M (d) 10.5 kg of Na2SO4 10H2O in 18.60 L of solution (e) 7.0 10−3 mol of I2 in 100.0 mL of solution (f) 1.8 104 mg of HCl in 0.075 L of solution
5.21. Determine the mass in grams of each of the following: (a) 0.600 mol of oxygen atoms (b) 0.600 mol of oxygen molecules, O2 (c) 0.600 mol of ozone molecules, O3
(a) 0.600 mol of oxygen atoms O=16g/mol 16g/mol x 0.600 mol = 9.6g (b) 0.600 mol of oxygen molecules, O2 O2=32g/mol 32g/mol x 0.600 mol = 19.2g (c) 0.600 mol of ozone molecules, O3 o3=48g/mol 48g/mol x 0.600 mol = 28.8g
5.18. Determine the number of moles of the compound and determine the number of moles of each type of atom in each of the following: (a) 2.12 g of potassium bromide, KBr (b) 0.1488 g of phosphoric acid, H3PO4 (c) 23 kg of calcium carbonate, CaCO3 (d) 78.452 g of aluminum sulfate, Al2(SO4)3 (e) 0.1250 mg of caffeine, C8H10N4O2
(a) 2.12 g of potassium bromide, KBr KBr=39+80=119g/mol 2.12g/(119g/mol)=0.0178 mol (b) 0.1488 g of phosphoric acid, H3PO4 H3PO4=(1•3)+31+(16•4)=98g/mol 0.1488g/(98g/mol)=0.0015 mol (c) 23 kg of calcium carbonate, CaCO3 (d) 78.452 g of aluminum sulfate, Al2(SO4)3 (e) 0.1250 mg of caffeine, C8H10N4O2
5.19. Determine the mass of each of the following: (a) 2.345 mol LiCl (b) 0.0872 mol acetylene, C2H2 (c) 3.3 10−2 mol Na2 CO3 (d) 1.23 103 mol fructose, C6 H12 O6 (e) 0.5758 mol FeSO4(H2O)7
(a) 2.345 mol LiCl LiCl=7+35=42g/mol 42g/mol x 2.345 mol = 98.48g (b) 0.0872 mol acetylene, C2H2 (c) 3.3 10−2 mol Na2 CO3 (d) 1.23 103 mol fructose, C6 H12 O6 (e) 0.5758 mol FeSO4(H2O)7
5.31. Which of the following represents the least number of molecules? (a) 20.0 g of H2O (18.02 g/mol) (b) 77.0 g of CH4 (16.06 g/mol) (c) 68.0 g of C3H6 (42.08 g/mol) (d) 100.0 g of N2O (44.02 g/mol) (e) 84.0 g of HF (20.01 g/mol)
(a) 20.0g/(18.02g/mol) = 1.11 mol (b) 77.0g/(16.06g/mol) = 4.79 mol (c) 68.0g/(42.08g/mol) = 1.62 mol (d) 100.0g/(44.02g/mol) = 2.27 mol (e) 84.0g/(20.01g/mol) = 4.20 mol (a) 20.0 g of H2O (18.02 g/mol) represents the least number of molecules
5.16. Determine the number of moles of compound and the number of moles of each type of atom in each of the following: (a) 25.0 g of propylene, C3H6 (b) 3.06 10−3 g of the amino acid glycine, C2H5NO2 (c) 25 lb of the herbicide Treflan, C13H16N2O4F (1 lb = 454 g) (d) 0.125 kg of the insecticide Paris Green, Cu4(AsO3)2(CH3CO2)2 (e) 325 mg of aspirin, C6H4(CO2H)(CO2CH3)
(a) 25.0 g of propylene, C3H6 C3H6=(12•3)+(1*6)=42g/mol 25.0g/(42g/mol)=0.595 mol (b) 3.06 10−3 g of the amino acid glycine, C2H5NO2 (c) 25 lb of the herbicide Treflan, C13H16N2O4F (1 lb = 454 g) (d) 0.125 kg of the insecticide Paris Green, Cu4(AsO3)2(CH3CO2)2 (e) 325 mg of aspirin, C6H4(CO2H)(CO2CH3)
5.8. Compare 1 mole of H2, 1 mole of O2, and 1 mole of F2. (a) Which has the largest number of molecules? Explain why. (b) Which has the greatest mass? Explain why.
(a) All H2, O2, and F2 have 2 molecules each. (b) F2 has the greatest mass at 38 while H2 has 2 and O2 has 32. (atomic mass of F=19, H=1, and O=16)
5.13. Calculate the molar mass of each of the following: (a) S8 (b) C5H12 (c) Sc2(SO4)3 (d) CH3COCH3 (acetone) (e) C6H12O6 (glucose)
(a) S8 32•8=256 g/mol (b) C5H12 (12•5)+(1•12)=72 g/mol (c) Sc2(SO4)3 (45•2)+(32+16•4)•3=90+(96•3)=378 g/mol (d) CH3COCH3 (acetone) 12+(1•3)+12+16+12+(1•3)=58 g/mol (e) C6H12O6 (glucose) (12•6)+(1•12)+(16•6)=72+12+96=180 g/mol
5.12. Calculate the molar mass of each of the following compounds: (a) hydrogen fluoride, HF (b) ammonia, NH3 (c) nitric acid, HNO3 (d) silver sulfate, Ag2SO4 (e) boric acid, B(OH)3
(a) hydrogen fluoride, HF HF=1+19=20 g/mol (b) ammonia, NH3 NH3=14+3=17 g/mol (c) nitric acid, HNO3 HNO3=1•14+16•2=47 g/mol (d) silver sulfate, Ag2SO4 Ag2SO4=108•2+32+16•4=312 g/mol (e) boric acid, B(OH)3 B(OH)3=11+(16+1)•3=62 g/mol
5.14. Calculate the empirical or molecular formula mass and the molar mass of each of the following minerals: (a) limestone, CaCO3 (b) halite, NaCl (c) beryl, Be3Al2Si6O18 (d) malachite, Cu2(OH)2CO3 (e) turquoise, CuAl6(PO4)4(OH)8(H2O)4
(a) limestone, CaCO3 (b) halite, NaCl (c) beryl, Be3Al2Si6O18 (d) malachite, Cu2(OH)2CO3 (e) turquoise, CuAl6(PO4)4(OH)8(H2O)4
5.15. Calculate the molar mass of each of the following: (a) the anesthetic halothane, C2HBrClF3 (b) the herbicide paraquat, C12H14N2Cl2 (c) caffeine, C8H10N4O2 (d) urea, CO(NH2)2 (e) a typical soap, C17H35CO2Na
(a) the anesthetic halothane, C2HBrClF3 (b) the herbicide paraquat, C12H14N2Cl2 (c) caffeine, C8H10N4O2 (d) urea, CO(NH2)2 (e) a typical soap, C17H35CO2Na
5.64. A throat spray is 1.40% by mass phenol, C6H5OH, in water. If the solution has a density of 0.9956 g/mL, calculate the molarity of the solution.
0.148 M
5.24. Determine which of the following contains the greatest mass of hydrogen: 1 mol of CH4, 0.6 mol of C6H6, or 0.4 mol of C3H8.
1 mol x (1•4) molecule = 4 molecules 0.6mol x (1•6) molecule = 3.6 molecules 0.4 mol x (1•8) molecule = 3.2 molecules 1 mol of CH4 has the greatest mass of hydrogen
5.23. Determine the number of atoms and the mass of zirconium, silicon, and oxygen found in 0.3384 mol of zircon, ZrSiO4, a semiprecious stone.
1 x 0.3384 mol x 6.022x10^23 = 2.038x10^23 atoms of Zr 1 x 0.3384 mol x 6.022x10^23 = 2.038x10^23 atoms of Si 4 x 0.3384 mol x 6.022x10^23 = 8.151x10^23 atoms of O Zr=91.224g/mol 91.224g/mol x 0.3384mol = 30.87g of Zr Si=28.086g/mol 28.086g/mol x 0.3384mol = 9.504g of Si O4=(15.999•4)=63.996g/mol 63.996g/mol x 0.3384mol = 21.656g of O
5.26. Diamond is one form of elemental carbon. An engagement ring contains a diamond weighing 1.25 carats (1 carat = 200 mg). How many atoms are present in the diamond?
1.25 carats = 1.25 x 0.2g = 0.25g C=12g/mol contains 6.022x10^23 atoms/mol (6.022x10^23 atoms/mol)/(12g/mol) x 0.25g = 0.125x10^23 atoms = 1.25x10^22 atoms
5.61. The hardness of water (hardness count) is usually expressed in parts per million (by mass) of CaCO3, which is equivalent to milligrams of CaCO3 per liter of water. What is the molar concentration of Ca2+ ions in a water sample with a hardness count of 175 mg CaCO3/L?
1.75×10^−3M
5.27. The Cullinan diamond was the largest natural diamond ever found (January 25, 1905). It weighed 3104 carats (1 carat = 200 mg). How many carbon atoms were present in the stone?
3104 carats = 3104 x 0.2g = 620.8g C=12g/mol contains 6.022x10^23 atoms/mol (6.022x10^23 atoms/mol)/(12g/mol) x 620.8g = 311.54x10^23 atoms = 3.1154x10^25 atoms
5.58. What mass of a 4.00% NaOH solution by mass contains 15.0 g of NaOH?
375 g
5.57. Consider this question: What mass of a concentrated solution of nitric acid (68.0% HNO3 by mass) is needed to prepare 400.0 g of a 10.0% solution of HNO3 by mass? (a) Outline the steps necessary to answer the question. (b) Answer the question.
58.8 g
5.22. A 55-kg woman has 7.5x10^−3 mol of hemoglobin (molar mass = 64,456 g/mol) in her blood. How many hemoglobin molecules is this? What is this quantity in grams?
7.5x10^-3 mol x 6.022x10^23 molecules/mol = 4.5165x10^21 molecules of hemoglobin 64,456g/mol x 7.5x10^-3 mol = 483.420g of hemoglobin
2.22. Explain what happens if even one amino acid is substituted for another in a polypeptide chain. Provide a specific example.
A change in gene sequence can lead to a different amino acid being added to a polypeptide chain instead of the normal one. Sickle-cell animia
5.25. Determine which of the following contains the greatest mass of aluminum: 122 g of AlPO4, 266 g of Al2Cl6, or 225 g of Al2S3.
AlPO4=27g/mol + 31g/mol + (16•4)g/mol = 122g/mol 122g/(122g/mol) x 27g/mol = 27g/mol of Al Al2Cl6=(27•2)g/mol + (35.453•6)g/mol = 266.7g/mol 266g/(266.7g/mol) x 54g/mol = 54g/mol of Al Al2S3=(27•2)g/mol + (32•3)g/mol = 150g/mol 225g/(150g/mol) x 54g/mol = 81g/mol of Al 225 g of Al2S3 contains the greatest mass of Al
Exercise 1.8 Give an example of how applied science has had a direct effect on your daily life.
Answers will vary. One example of how applied science has had a direct effect on daily life is the presence of vaccines. Vaccines to prevent diseases such polio, measles, tetanus, and even the influenza affect daily life by contributing to individual and societal health.
3.1. Figure 3.7 Why was Dolly a Finn-Dorset and not a Scottish Blackface sheep?
Because even though the original cell came from a Scottish Blackface sheep and the surrogate mother was a Scottish Blackface, the DNA came from a Finn-Dorset.
2.17. Why can some insects walk on water?
Because of the cohesion and the high surface tension of water due to weak hydrogen bonds
2.2. The kidneys are responsible for removing excess H+ ions from the blood. If the kidneys fail, what would happen to blood pH and to hemoglobin affinity for oxygen?
Blood pH will decrease (become more acidic) Hemoglobin affinity for oxygen will be reduced
5.29. A certain nut crunch cereal contains 11.0 grams of sugar (sucrose, C12H22O11) per serving size of 60.0 grams. How many servings of this cereal must be eaten to consume 0.0278 moles of sugar?
C12H22O11= (12•12)+(1•22)+(16*11)=144+22+176=342g/mol 342g/mol x 0.0278 mol = 9.5076 g 9.5076g/11g (sugar per 1 serving) = 0.86 servings
5.20. The approximate minimum daily dietary requirement of the amino acid leucine, C6H13NO2, is 1.1 g. What is this requirement in moles?
C6H13NO2=(12•6)+(1•13)+14+(16•2)=72+13+14+32=131g/mol 1.1g/(131g/mol)=0.0084 mol
2.20. How does the administration of 100 percent oxygen save a patient from carbon monoxide poisoning? Why wouldn't giving carbon dioxide work?
Carbon monoxide has a higher affinity for hemoglobin than oxygen. This means that carbon monoxide will preferentially bind to hemoglobin over oxygen. Administration of 100 percent oxygen is an effective therapy because at that concentration, oxygen will displace the carbon monoxide from the hemoglobin.
5.34. A 200-mL sample and a 400-mL sample of a solution of salt have the same molarity. In what ways are the two samples identical? In what ways are these two samples different?
Concentrations (molarity) are the same Number of moles and volume are different
5.7. Write a sentence that describes how to determine the number of moles of a compound in a known mass of the compound if we know its molecular formula.
Determine molecular mass from its molecular formula, then divide known mass by molecular mass to determine the numbers of moles of the compound.
5.10. Which contains the greatest number of moles of oxygen atoms: 1 mol of ethanol (C2H5OH), 1 mol of formic acid (HCO2H), or 1 mol of water (H2O)? Explain why.
Formic Acid 0.75 mol x 1 oxygen atom = 0.75 mol of O 0.60 mol x 2 oxygen atom = 1.20 mol of O 1.0 mol x 1 oxygen atom = 1.0 mol of O
5.9. Which contains the greatest mass of oxygen: 0.75 mol of ethanol (C2H5OH), 0.60 mol of formic acid (HCO2H), or 1.0 mol of water (H2O)? Explain why.
Formic Acid 0.75 mol x 1 oxygen atom = 0.75 mol of O 0.60 mol x 2 oxygen atoms = 1.20 mol of O 1.0 mol x 1 oxygen atom = 1.0 mol of O
3.8. Today, it is possible for a diabetic patient to purchase human insulin from a pharmacist. What technology makes this possible and why is it a benefit over how things used to be?
Recombinant DNA (rDNA) technology: Human DNA is spliced using restriction enzymes into the plasmid of common bacterium such as E. coli for rapid replication. Speed/quantity (bacteria replicates very quickly) and safety over pig insulin
5.6. Which molecule has a molecular mass of 28.05 amu?
Si (Silicone)
5.28. One 55-gram serving of a particular cereal supplies 270 mg of sodium, 11% of the recommended daily allowance. How many moles and atoms of sodium are in the recommended daily allowance?
Sodium on Nutrition label Na or NaCl? Using Na here. 0.270g/11% = 2.4545g is daily recommendation Na=22.990g/mol 2.454g/(22.990g/mol) = 0.1068 mol 0.1068mol x 6.022x10^23 atoms/mol = 0.643x10^23 atoms =6.43x10^22 atoms
Exercise 1.5 Figure 1.18 In the example below, the scientific method is used to solve an everyday problem. Which part in the example below is the hypothesis? Which is the prediction? Based on the results of the experiment, is the hypothesis supported? If it is not supported, propose some alternative hypotheses. 1. My toaster doesn't toast my bread. 2. Why doesn't my toaster work? 3. There is something wrong with the electrical outlet. 4. If something is wrong with the outlet, my coffeemaker also won't work when plugged into it. 5. I plug my coffeemaker into the outlet. 6. My coffeemaker works.
The hypothesis is #3 (there is something wrong with the electrical outlet), and the prediction is #4 (if something is wrong with the outlet, then the coffeemaker also won't work when plugged into the outlet). The original hypothesis is not supported, as the coffee maker works when plugged into the outlet. Alternative hypotheses may include (1) the toaster might be broken or (2) the toaster wasn't turned on.
2.16. Why are hydrogen bonds and van der Waals interactions necessary for cells?
They form weaker associations between molecules or within different regions of the same molecule. They provide the structure and shape necessary for proteins within DNA cells so that they function properly
2.5. An isotope of sodium (Na) has a mass number of 22. How many neutrons does it have? a. 11 b. 12 c. 22 d. 44
a. 11
2.3. Magnesium has an atomic number of 12. Which of the following statements is true of a neutral magnesium atom? a. It has 12 protons, 12 electrons, and 12 neutrons. b. It has 12 protons, 12 electrons, and six neutrons. c. It has six protons, six electrons, and no neutrons. d. It has six protons, six electrons, and six neutrons.
a. It has 12 protons, 12 electrons, and 12 neutrons.
3.4. What carries a gene from one organism into a bacteria cell? a. a plasmid b. an electrophoresis gel c. a restriction enzyme d. polymerase chain reaction
a. a plasmid
2.9. Which of the following will NOT facilitate the transfer of oxygen to tissues? a. decreased body temperature b. decreased pH of the blood c. increased carbon dioxide d. increased exercise
a. decreased body temperature
2.4. Which type of bond represents a weak chemical bond? a. hydrogen bond b. ionic bond c. covalent bond d. polar covalent bond
a. hydrogen bond
Exercise 1.6 A suggested and testable explanation for an event is called a ________. a. hypothesis b. variable c. theory d. control
a. hypothesis
2.14. Phospholipids are important components of __________. a. the plasma membrane of cells b. the ring structure of steroids c. the waxy covering on leaves d. the double bond in hydrocarbon chains
a. the plasma membrane of cells
3.5. What is a genetically modified organism (GMO)? a. a plant with certain genes removed b. an organism with an artificially altered genome c. a hybrid organism d. any agricultural organism produced by breeding or biotechnology
b. an organism with an artificially altered genome
3.2. In gel electrophoresis of DNA, the different bands in the final gel form because the DNA molecules ________. a. are from different organisms b. have different lengths c. have different nucleotide compositions d. have different genes
b. have different lengths
2.8. The pH of lemon juice is about 2.0, whereas tomato juice's pH is about 4.0. Approximately how much of an increase in hydrogen ion concentration is there between tomato juice and lemon juice? a. 2 times b. 10 times c. 100 times d. 1000 times
c. 100 times
3.6. What is the role of Agrobacterium tumefaciens in the production of transgenic plants? a. Genes from A. tumefaciens are inserted into plant DNA to give the plant different traits. b. Transgenic plants have been given resistance to the pest A. tumefaciens. c. A. tumefaciens is used as a vector to move genes into plant cells. d. Plant genes are incorporated into the genome of Agrobacterium tumefaciens.
c. A. tumefaciens is used as a vector to move genes into plant cells.
2.15. The monomers that make up proteins are called _________. a. nucleotides b. disaccharides c. amino acids d. chaperones
c. amino acids
2.10. The majority of carbon dioxide in the blood is transported by ________. a. binding to hemoglobin b. dissolution in the blood c. conversion to bicarbonate d. binding to plasma proteins
c. conversion to bicarbonate
2.7. Using a pH meter, you find the pH of an unknown solution to be 8.0. How would you describe this solution? a. weakly acidic b. strongly acidic c. weakly basic d. strongly basic
c. weakly basic
2.6. Which of the following statements is not true? a. Water is polar. b. Water stabilizes temperature. c. Water is essential for life. d. Water is the most abundant atom in Earth's atmosphere.
d. Water is the most abundant atom in Earth's atmosphere.
3.3. In the reproductive cloning of an animal, the genome of the cloned individual comes from ________. a. a sperm cell b. an egg cell c. any gamete cell d. a body cell
d. a body cell (somatic cell)
2.12. An example of a monosaccharide is ________. a. fructose b. glucose c. galactose d. all of the above
d. all of the above
2.11. The majority of oxygen in the blood is transported by ________. a. dissolution in the blood b. being carried as bicarbonate ions c. binding to blood plasma d. binding to hemoglobin
d. binding to hemoglobin
Exercise 1.7 The type of logical thinking that uses related observations to arrive at a general conclusion is called ________. a. deductive reasoning b. the scientific method c. hypothesis-based science d. inductive reasoning
d. inductive reasoning
2.13. Cellulose and starch are examples of ________. a. monosaccharides b. disaccharides c. lipids d. polysaccharides
d. polysaccharides
