Chemistry 100 Final Study Guide - Brigham Young University ...



Chemistry 100 Final Study Guide Key

• Chapter 1: Introduction

a. Physical vs. Chemical properties

1) Physical properties: shiny, metallic, malleable, ductile, conductive. Chemical property: reactive with water.

b. Units of measurement

1) Meters, liters, grams (with any prefixes) are metric system. All others are U.S.

2) 5.68 x 10-7 46,300,000

c. Density

1) 2.47g/mL

• Chapter 3: Atomic Structure

a. Historical Perspective

1) List the major scientific accomplishment of the following scientists:

i) Experiments in electrochemistry described ions and the electrical nature of atoms

ii) Cathode-ray tube experiments led to the proposal of the “Plum pudding” model of atoms

iii) Oil-drop experiments calculated the mass of electrons

iv) Gold foil experiments proved atoms had a dense, positively-charged nucleus and empty space

v) Proposed an atomic model with a nucleus and electrons circling like planets

vi) Proposed that electrons exist in a “cloud” or probability region around the nucleus

b. Isotopes

1) Isotopes of an element have the same number of protons, but different numbers of neutrons. Regular hydrogen has 1 proton and no neutrons. Isotopes could have 1 proton and 1 neutron (deuterium) or 1 proton and 2 neutrons (tritium).

c. Structure of the atom

1) Protons and neutrons are in the nucleus. Electrons are in regions of space surrounding the nucleus.

2) 3 energy levels, 4 sublevels, 6 orbitals, 11 electrons

3) 1s22s22p63s23p2

d. Electron configurations and trends on the Periodic Table

1) See the periodic Table.

• Chapter 5: Chemical bonds

a. Electron-dot structures

1) Draw the electron-dot structure of an oxygen atom.

b. Octet Rule and Ions

1) Mg2+, Cl-, N3-

c. Ionic compounds

1) Aluminum bromide, calcium sulfide, sodium nitride

d. Covalent compounds

1) Sulfur dioxide, phosphorus trichloride, carbon tetrahydride

e. Polyatomic molecules

1) Nitrate (NO3-), chlorate (ClO3-), carbonate (CO32-), sulfate (SO42-), chromate (CrO42-), phosphate (PO43-)

f. Electron-dot formulas for molecules

1) Answer will be given in class.

g. VSEPR Model and Molecular shape

VSEPR shape = pyramidal

h. Molecule polarity

1) Non-polar = linear, triangular, tetrahedral. Polar = pyramidal, bent, bent

i. Intermolecular forces

1) Polar covalent, Hydrogen bonding; non-polar covalent, dipole-dipole attraction; polar covalent, dipole-dipole attraction; polar covalent, dispersion force

• Chapter 6: Chemical Quantities

a. Atomic mass & formula mass

1) Atomic mass = 30.97amu. Formula mass = 137.32g / mol

b. The mole: Avogadro’s number and molar mass

1) 6.022 x 1023

2) 44.01g / mol

c. Chemical Equations

1) 2Fe2O3 + 3C ( 3CO2 + 4Fe

2) Na2CO3 + 2KClO3 ( 2NaClO3 + K2CO3

d. Molar proportions

1) N2 + 3H2 ( 2NH3 I need 9 moles of hydrogen gas to make 6 moles of ammonia. If I begin with 14.2g of N2, I will form 17.27g of NH3.

• Chapter 7: Acids and Bases

a. Definitions and Characteristics

1) Acids: sour, donate an H+ in solution, turn litmus paper red. Bases: bitter, feel soapy, accept an H+ in solution, turn litmus paper blue.

b. Strong vs. Weak

1) How readily it comes apart (dissociates) in water

c. Acid-base neutralization reactions

1) Ca(OH)2 + H2CO3 ( 2H2O + CaCO3; products are water and calcium carbonate

d. The pH scale

1) Basic, Acidic, neutral

2) 10,000 times more acidic

e. pH Calculations

1) pH = 2.24

2) [H+] = 3.98 x 10-13 M

f. Acids and bases in your life

1) Acids in our lives: acid rain, stomach acid, batteries. Bases: antacids, cleaning, baking soda.

• Chapter 8: Oxidation and Reduction

a. Definitions

1) Oxidation = loss of electrons. Reduction = gain of electrons.

b. Assigning Oxidation Numbers

1) CH4 = hydrogen +1, carbon -4. CO2 = oxygen -2, carbon +4. Carbonite (CO22-) = oxygen -2, carbon +2.

c. Oxidation-reduction (redox) reactions

1) C2H4 + 3O2 ( 2CO2 + 2H2O. Carbon = being oxidized (-2 ( +4), acts as reducing agent. Oxygen = being reduced (0 ( -2), acts as oxidizing agent.

d. Oxidation and reduction in your life

1) Batteries = lead storage batteries (lead being both oxidized and reduced), dry cell batteries (zinc being oxidized, manganese being reduced). Corrosion = iron oxidized to rust, silver oxidized to tarnish, copper oxidized to green compound (e.g. on Statue of Liberty). Combustion = carbon being oxidized. Photography = silver ions being reduced to metallic silver.

• Chapter 9: Organic Chemistry

a. Know the prefixes for naming carbon compounds

1) Prop--, Pent--, Eth--

b. Be able to recognize molecules of the following: alkanes, alkenes, alkynes, alcohols, amines, esters, amides, carboxylic acid

c. Be able to draw and name molecules of the following: alkanes, alkenes, alkynes, alcohols, amines

d. Be able to draw molecules containing amide, ester or carboxylic acid groups

e. Characteristics of organic molecules

1) Saturated = alkanes. All others are unsaturated.

2) Generally, molecules with less than 4 carbons = gas. 5-16 carbons = liquid. Above 18 = solid.

3) Alkanes, alkenes, alkynes = used as fuels, lubricants, starting materials for industrial processes. Alcohols = used for recreation, for cleaning. Amines = used in making proteins & DNA. Esters = used as flavors and fragrances. Amides = wool, nylon, silk, linkages in protein molecules. Carboxylic acid = ends of fatty acids that bond to glycerol to make trigylcerides

• Chapter 10: Polymers

a. Forming a polymer

1) Polymer is a Latin word meaning “many parts.” A polymer is a chain of repeating carbon subunits bonded together. Monomer is a Latin word meaning “one part.” It is the subunit, or single part, that repeats and is joined together to form a longer polymer.

2) Heat, pressure, and a catalyst

b. Addition polymerization

1) Addition polymerization is simply adding additional parts onto an existing carbon chain.

2) See page 285 in our text, and our PowerPoint. You should be able to draw the bracket structure of the monomers of polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, polytetrafluoroethylene, and polyacrylate

c. Condensation polymerization

1) Condensation polymerization is adding monomers together in a chain by removing a water molecule and bonding together the remaining parts.

2) Polyester, nylon, polyurethane (foam rubber)

d. Natural polymers

1) Protein, DNA, starch, rubber

2) Rubber’s monomer is isoprene. See pg. 286 in our text.

3) Vulcanization is the process of making rubber stronger through the addition of sulfur linkages (or “bridges”) between neighboring chains of polyisoprene. The process requires heat and sulfur. Vulcanized rubber is used in car tires, rubber bands, and racquetballs.

• Chapter 15: Biochemistry

a. Carbohydrates

1) Sugar = monosaccharides, names end in –ose (e.g. glucose, fructose). Starch = polysaccharides, many sugars linked together. Plant starch is called amylose, stored in granules. Animal starch is called glycogen, stored in muscles. Cellulose = a polysaccharide with different linkages than starch (indigestible to humans).

b. Fats

1) Fatty acids, waxes, steroids, fat-soluble vitamins. Fats are generally less dense and insoluble in water.

c. Proteins

1) All proteins are composed of amino acids.

2) Primary structure = amino acids linked together with amide linkages (peptide bonds). Secondary structure = hydrogen bonds turn the primary structure into alpha-helix or beta-pleated sheets. Tertiary structure = hydrogen bonds, disulfide bonds (covalent), salt bridges (ionic), and dispersion forces shape the secondary structures into a 3-dimensional protein. Quaternary structure = same types of bonds as tertiary structure, linking together different folded amino acid chains.

3) An enzyme is a protein that speeds up (catalyzes) reactions by bringing the reactants close together while they react, then letting them go. The enzyme is very specifically shaped to bond only onto the molecules in certain reactions, but it can be used over and over since it is not used up in the reaction.

d. Nucleic acids

1) Sugar, phosphate groups, amine bases

2) Purines = adenine (A), guanine (G). Pyrimidines = thymine (T), cytosine (C), uracil (U). Purines always bond with pyrimidines. A – T, G – C, U replaces T in RNA and bonds with A.

3) In DNA replication, the original double strand of DNA unzips. The exposed amine bases are paired up with new nucleotides (there are free nucleotides in the nucleus) and bonded into a new strand of DNA. When finished, we have 2 complete copies of the double-stranded DNA, each with 1 old strand from the original DNA and 1 new strand.

4) DNA in the nucleus unzips. mRNA (messenger RNA) forms a copy of the DNA that will code for a new protein. The mRNA is a negative copy of the original DNA, and it is different from the DNA because it is only single-stranded and it uses uracil to bond with adenine, rather than thymine. Other than that, the mRNA is very similar to the DNA. The DNA re-bonds, and the mRNA leaves the nucleus. In the cytoplasm of the cell, tRNA molecules come bond to the mRNA strand. The tRNA molecules have a 3 base sequence at one end that bonds to the complimentary bases in the mRNA, and it carries an amino acid at the other end. As the tRNAs line up along the mRNA, the amino acids are bonded together with amide linkages (also called peptide bonds). This chain of amino acids is the primary structure of a new protein.

5) Crime scene analysis = matching DNA from suspects to DNA found at the scene of a crime. Paternity testing = matching a child’s DNA with a suspected parent’s DNA.

• Chapter 16: Food Chemistry

a. Carbohydrates

1) Carbohydrates are broken down into glucose (monosaccharide). Pros of low-carb diet: lose weight quickly, good for sustained energy (high protein). Cons of low-carb diet: long-term NOT good for body, problems with digestion, usually nutritionally poor

b. Fats

1) Fats are broken down into fatty acids. Our body uses lipoproteins to carry fats: HDL (high-density lipoprotein), LDL (low-density) and VLDL (very low-density). Fats are good because we need them for energy and energy storage, for repairing cell membranes and brain tissue, and for fat-soluble vitamins. Too much fat, however, can lead to obesity, atherosclerosis, high cholesterol and other health problems.

2) Trans-fatty acids are unsaturated, similar in structure to their cousins cis-fatty acids except for the arrangement of the molecule around the double bond. The way the trans molecule is arranged allows the trans-fats to be stacked together very tightly like saturated fats, but not broken down as easily. This allows them to build up in arteries and organs, leading to health problems. They are BAD.

c. Proteins

1) Proteins are broken down into amino acids. Vegetarians can get enough proteins by mixing legumes and cereal grains

d. Minerals

1) Iodine = thyroid health (protect against goiter). Calcium = bone health, muscle contraction. Sodium = cell signaling, electrolyte balance in fluid systems. Iron = oxygen transport in the blood. Phosphorus = energy exchange (ATP)

e. Vitamins

1) Fat-soluble vitamins (A, D, E, K) are stored in our fat cells so we can build up a supply. Water-soluble vitamins (B and C) are excreted when in excess, so we can only use so much at a time.

f. Dietary fiber

1) Both types of fiber are equally important. Both types add bulk so I feel full, help move along digestion, add texture to food, and may help lower cholesterol and control blood sugar. The only difference between soluble and insoluble fiber is that insoluble fiber (cellulose) is not broken down in our bodies, while soluble fiber is actually a very complex carbohydrate that is eventually broken down into glucose.

g. Water

1) Water is critical because our bodies are at least ¾ water, and our brains are an even higher percentage. Symptoms of dehydration include headaches, water retention, joint pain, excess body fat stored, buildup of toxins in blood, poor muscle tone, poor digestion.

h. Food additives

1) BHT, vitamin C, sulfur dioxide, sodium nitrate

2) Folic acid, vitamin C, riboflavin, thiamine, niacin

3) Sugar, salt, MSG, flavorings (esters – vanilla, lemon, almond, etc.)

4) Natural = turmeric, caramel, beta carotene, chlorella, beet juice, saffron, annatto. Artificial = FD&C dyes and lakes

i. Food poisons

1) Chemical = saffrole, benzopyrene (from charbroiled food). Biological = botulism toxin, salmonella toxin

j. Plant nutrients and fertilizers

1) Nitrogen, phosphorus, potassium. On a bag of fertilizer, these appear as 3 numbers, for example 10-5-20. This tells me the percentage by mass of each one in the fertilizer. Too much of any of these nutrients can cause pollution of the water, but especially phosphorus. Phosphorus causes overgrowth of algae which can kill fish and lead to collapse of ecosystems.

k. Pest control

1) Chemical and Biological. Chemical controls = chlorinated hydrocarbons (e.g. DDT) or organic phosphorus compounds. Pros = work quickly and effectively, easy to apply, cheap to make. Cons = pollution in the environment, also toxic to humans, lead to insect resistance. Biological controls = sterilization, juvenile hormones, insect-specific viruses. Pros = usually quite effective without environmental pollution, can be very specific. Cons = expensive, difficult to apply, possible danger to humans (e.g. insect viruses could mutate).

l. All food is put here for our use, but to be used in moderation!

• Chapter 17: Common Chemicals

a. Soap vs. detergent

1) Soap and detergent are both used to clean because they contain surfactants—this allows a suspension of non-polar molecules (e.g. dirt, oil) in a polar solvent (e.g. water). Soap also has cross-reactions in hard water with the minerals, leaving behind insoluble soap scum. It is better to use soap in soft water where these reactions are minimized. Detergent does not react with minerals, so it is fine to use in any type of water.

b. Cleaners

1) Regular bleach oxidizes the colored pigments in stains to colorless products. “Color-safe” bleach is actually only an optical brightener—the clothes appear whiter because they are coated with a pigment that reflects blue light to our eyes.

2) Acidic = toilet bowl cleaner, vinegar. Basic = drain cleaner, ammonia.

c. Skin care

1) Surfactant = stabilizes a suspension of non-polar solutes in a polar solvent. Emollient = moisturizes by coating surfaces to minimize water loss. Exfoliant = removes surface skin cells, either by breaking them down (chemical) or physically scraping them off (mechanical). Humectant = moisturizes by hydrogen-bonding to water molecules to prevent them from evaporating. Astringent = causes pore restriction.

2) Sunscreens chemically absorb UV rays that enter the skin before they can cause damage. Sunblocks physically block UV rays from penetrating the skin because they contain metals that reflect the energy.

3) Sunscreens and sunblocks both protect against UVA and UVB radiation, 2 ranges of ultraviolet wavelengths.

4) Sunscreens = Octyl methyloxycinnamate, oxybenzone, octyl salicylate, avobenzone; sunblocks = zinc oxide, titanium dioxide

5) SPF is “sun protection factor”, the number of times more protection given by the sunscreen/sunblock than natural skin possesses. An SPF 20 would protect me from 95% of the UV rays hitting me.

d. Hair care

1) Hair perms work by placing the hair in the desired shape then adding a reducing agent that breaks the disulfide (covalent) bonds that hold the hair strand together. An oxidizing agent finally stops the bond breakage, allowing the hair to re-form disulfide bonds in whatever shape it’s been given. Shampoo is a detergent that cleans away dirt and oil from the hair. Conditioner is usually silk proteins or dimethicone or other substances that coat the hair shaft to smooth down the scales and reduce friction between hair strands. Hair color is dye molecules that penetrate into the hair shaft and remain permanently, except for blond hair color which is oxidation of the hair’s natural color molecules (melanins) to colorless products. Hairspray is a solution of sticky polymers and alcohol—when sprayed on hair, the alcohol evaporates and leaves behind the sticky polymers that glue the hair shafts together. Depilatories are basic solutions that break the peptide bonds between amino acids in the proteins of the hair, causing the hair itself to fall apart and fall out.

a. Brain

1) Be able to recognize parts of a neuron.

2) Neurotransmitters: chemical messengers

• Chapter 19: Drug Chemistry

a. Curative Drugs

1) Penicillin was discovered in the 1800’s by Alexander Flemming when he noticed mold growing on some of his bacterial samples. Penicillin works by inhibiting an enzyme bacteria need to build cell walls, so their membranes leak and they die. Problems with penicillin include increasing bacterial resistance and possible allergies (people who are allergic to certain types of molds).

2) Alkylating drugs add extra pieces (alkyl groups) onto cancer cell proteins so that they don’t function the way they should and the cell ultimately dies. An example of this type of drug is mustard gas. Anti-metabolite drugs physically prevent the cancer cell DNA from replicating so the cells can’t continue to divide. An example of this type of drug is cisplatin.

b. Regulatory drugs

1) Oxytocin is a hormone produced in the brain. It causes smooth muscle contraction, so it is often used to induce labor in pregnant women. Human growth hormone is also produced in the brain—this causes bone and tissue growth.

2) Cortisol is produced in the adrenals. This is a hormone produced during times of stress that help the body calm down and reset its fight-or-flight mechanisms. Because of this, it is often used to treat severe allergies and anaphylactic shock, situations of the body’s extreme reaction to stress. Adrenaline is also produced in the adrenals, which helps induce a fight-or-flight reaction.

3) Estrogen and testosterone are produced in the sex organs. These hormones cause expression of female and male physical characteristics.

c. Preventative Drugs

1) Mental illness

i) Axon, dendrite, cell body

ii) Neurotransmitters

a) Serotonin is made from the amino acid tryptophan. It functions in mood regulation and sleep.

b) Norephinephrine is made from the amino acid tyrosine. It functions in fight-or-flight responses (stress situations), attention and impulsivity.

c) Dopamine is made from the amino acid tyrosine. It functions in movement and sympathetic nervous system (involuntary body systems).

d) Acetylcholine is made from the vitamin choline. It functions in muscle contraction and stress situations.

iii) Treating mental illness

a) Some drugs mimic or enhance the action of natural neurotransmitters. Norepinephrine can be used to treat depression because it speeds up body processes and helps the patient feel more alert and alive. Serotonin can be used to treat both depression and mania because it is a major factor in mood control and it can help overactive patients feel more calm and focused.

b) Drugs can also control how messages are sent/received in the brain. MAOIs (monoamine oxidase inhibitors) prevent the enzyme monoamine oxidase from deactivating the chemical messengers, so the message has a greater chance of being received. These drugs affect all neurotransmitters. Other drugs affect specific neurotransmitters, and keep them from being reabsorbed into the neuron sending the message (reuptake). This also gives the chemical messengers a greater chance of reaching the intended receptor. Examples are SSRIs (selective serotonin reuptake inhibitors), NARIs (noradrenaline reuptake inhibitors), and SNRIs (serotonin-noradrenaline reuptake inhibitors).

2) Hypertension is when the blood pressure is too high. It is treated by diuretics, which reduce blood volume so the heart has less to pump. Coronary artery disease is when deposited fats build up on the blood vessel walls, restricting the flow of blood. This is treated by nitroglycerin, which dilates the vessels to allow more passage of blood.

3) “The pill” is composed of progestins, which mimic the body’s natural pregnancy hormones, making the body think it’s pregnant. Therefore, no ovulation takes place and there is no chance of becoming pregnant. RU-486 and DES are taken after possible fertilization and implantation occur—they cause the uterine lining to slough off, thus destroying any developing embryo.

d. Analgesics and Anesthetics

1) Aspirin is an analgesic, novocaine is an anesthetic. Both are used in the treatment of pain, but they work by different means. Analgesics block pain messengers to the brain, so they work without affecting other body systems. Anesthetics are systemic depressants, causing unconsciousness and general insensitivity to pain.

2) NSAID = non-steroidal anti-inflammatory drug

3) Pros = effective at reducing fever and easing pain by blocking chemical messengers (prostaglandins) that travel to the brain. Been used for centuries, well studied. Can be used as a blood thinner. Cons = acidic, so can cause stomach irritation and possible damage; some people have allergies; can cause problems with blood clotting since it affects chemicals that platelets use to form clots; can also cause damage in kidneys and the GI tract

e. Recreational drugs.

1) Depressant = alcohol. Works by slowing down all body systems, similar to anesthetics but usually on a lesser scale. Stimulant = caffeine, methamphetamines. Mimics actions of adrenaline and norepinephrine, induce body’s fight-or-flight mechanisms. Narcotic = morphine, heroin. Works by acting on opiate receptors in the brain to produce feelings of euphoria and insensitivity to pain. Psychedelic = marijuana, PCP. Works by altering the way the brain works (altered perception of reality) and possibly mimicking natural substances in the body that are only made under extreme circumstances (near death). There are some legitimate uses of recreational drugs: caffeine is used in conjunction with analgesics to speed up pain relief; marijuana is used to treat glaucoma; alcohol is used as a cleansing agent and disinfectant topically; morphine (and heroin in other countries) is used for pain relief of terminally ill patients.

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