Exam 3: CHEM120/ CHEM120 (2026/2027 Update) – General, Organic & Biological Chemistry | Questions & Answers | Verified Solutions | Chamberlain

…..DLDD Exam 3: CHEM120/ CHEM120 (2026/2027 Update) – General, Organic & Biological Chemistry | Questions & Answers | Verified Solutions | Chamberlain Q. How many nonbonding electron pairs (lone pairs) are present in H-Br? Answer 3 Q. How many bonding electron pairs are present in N? Answer 3 Q. How many bonds does nitrogen typically form? Answer Three Q. Which of the following statements contrasting covalent bonds and ionic bonds is correct? Answer Covalent bonds usually involve two nonmetals and ionic bonds usually involve a metal and nonmetal Q. Which atom in chlorous acid (HCLO2) are involved in a coordinate covalent bond? Answer Oxygen and chlorine Q. How many valence electrons are in the lewis structure for C2H3O2? Answer 24 Q. What is the VSEPR theory based on? Answer Electrons pairs in the valence shell of an atom adopt an arrangement in space that minimizes the repulsions between the like-charged electron pairs Q. If the central atom in a molecule has four electron groups, it is ____________ and has bond angles of ____________. Answer Tetrahedral; 109 degrees Q. How many electron groups does the central atom in CO2 contain? Answer Two Q. If the central atom in a molecule contains 3 electron groups and 1 lone pair, the molecular geometry is _______________. Answer Bent/angular Q. what is the molecular geometry for H2O? Answer Bent/angular Q. What is electronegativity? Answer A measure of the relative attraction that an atom has for the shared electrons in a bond Q. Which of the following elements are arranged in order of increasing electronegativity? Answer Rb Sn As Q. A __________________ bond is a covalent in which there is unequal sharing of electrons between two atoms. Answer Polar Q. The electronegativity difference between C and F is 1.5. The C-F bond is Answer Polar Covalent Q. Which of the following molecules is Polar? Answer NH3 Q. Which of the following is nonpolar? Answer CH4 Q. Which of the following is named incorrectly? Answer SF4- Sulfur Heptafluride Q. Which of the following is named correctly? Answer MgCl2- Magnesium Chloride Q. Which of the following linear molecules is a nonpolar molecule containing polar bonds? Answer O = C = O Q. Which of the following compounds contains both ionic and covalent bonds? Answer LiCN Q. In which of the following molecular compounds are all the bonds single bonds Answer NBr3 Q. What is the formula mass of Al2(SO4)3? Answer 342.17 amu Q. How many atoms ar in 5.6 moles of Ca(OH)2? the formula mass of Ca(OH)2 is 74.10 amu. Answer 3.4 x 10 to the 24th Q. Calculate the mass, in grams, of a 4.5 mole sample of Ca(OH)2. Answer 330 grams Q. How many grams of oxygen (O) are in 56 grams of Ca(OH)2? Answer 24 grams Q. How many moles of carbon (C) atoms are in a 1.2 mole sample of C6H12O6? Answer 7.2 mol Q. How many atoms of hydrogen (H) are in 3.4 moles of C6H12O6? Answer 2.5 x 10 to the 25th Q. Expression the following statement as a chemical equation: "sodium hydroxide reacts with hydrogen chloride to form sodium chloride to form sodium chloride and water." Answer NaOH + HCl - NaCl + H2O Q. Which of the following elements does not exist as a monaatomic gas? Answer At Q. Which of the following does not exist as a diatomic gas? Answer S Q. What coefficient is placed in front of O2 to balance the following chemical equation? ____C4H10 + ______O2 ---- _____CO2 + ____H2O Answer 13 Q. What coefficient is placed in front of NaCl to balance the following chemical equation? _____ Fe(SO4)3 + _____ NaCl ----- _____ FeCl3 + _____ Na2SO4 Answer 6 Q. In atoms, electrons will occupy the lowest energy orbitals available Answer aufbau principle Q. The assignment of all of the electrons in an atom into specific shells and subshells Answer electron configuration Q. How many electrons can an s subshell hold Answer 2 Q. How many electrons can a p subshell hold Answer 6 Q. How many electrons can a d subshell hold Answer 10 Q. How many electrons can each orbital in an electron configuration hold Answer 2 Q. Two electrons in the same orbital cannot have the same spin Answer pauli exclusion principle Q. Representation of the orbitals in a subshell as boxes and the electrons in them as arrows Answer orbital diagram Q. What are the up and down arrows in an orbital diagram represented as? Answer the spin of the electron; either clockwise or counter clockwise Q. Two opposite-spin electrons in one orbital diagram are _____ Answer paired Q. Electrons occupy separate orbitals in the same subshell with parallel spins (electrons repel each other) Answer Hund's rule Q. The distance from the nucleus to the outer most electrons in an atom Answer atomic radius Q. How is atomic radius usually measured Answer in nm or pm Q. What's the periodic trend for atomic radius? Answer going down a column increases, going right to left on a row increases Q. The energy required to remove an electron from an atom to form a 1+ ion Answer ionization energy Q. Why is ionization energy a positive value? Answer because energy is required for this Q. What's the periodic trend for ionization energy? Answer going up a column increases, going left to right on a row increases Q. The tendency of an atom to gain an electron to form a -1 ion Answer electron affinity Q. what's the opposite of electron affinity Answer ionization energy Q. Why is electron affinity a negative value? Answer because energy is gained through this Q. What group is electron affinity positive for and why? Answer noble gases because they already have filled orbitals Q. The distance from the nucleus to the outermost electron of an ion Answer ionic radius Q. Cations have a _____ charge Answer positive Q. Anions have a ____ charge Answer negative Q. which has a bigger ionic radius? cations or anions? Answer anions Q. which has a smaller ionic radius? cations or anions? Answer cations Q. How do you determine if a bond is polar? Answer if the difference in electronegativity is greater than 0 but less than 1.8 Q. How do you determine if a bond is ionic in terms of electronegativity? Answer if the difference in electronegativity is greater than 1.8 Q. Electron pairs (either bonds or unshared pairs of electrons) repel each other as much as possible Answer valence shell electron pair repulsion theory (vsepr) Q. The geometry formed by all of the covalent bonds AND lone pairs of electrons around the central atom Answer electronic geometry Q. If there are 2 electron groups, what is the electron geometry and bond angle? Answer linear; 180 deg Q. if there are 3 electron groups, what is the electron geometry and bond angle? Answer trigonal planar, 120 deg Q. if there are 4 electron groups, what is the electron geometry and bond angle? Answer tetrahedral, 109.5 deg Q. geometry formed by only the bonded atoms around the central atom... lone pairs are invisible Answer molecular geometry what makes a molecular and an electron geometry the same? if there are no lone pairs if there are 3 electron groups with 2 atoms and one lone pair, what's the molecular geometry and angle? v shaped; approx 120 deg if there are 4 electron groups with 3 atoms and one lone pair, what's the molecular geometry and angle? trigonal pyramid if there are 4 electron groups with 2 atoms and 2 lone pairs, what's the molecular geometry and angle? v shaped; approx 109 deg the combined polarities of the bond dipoles of all the bonds in a molecule molecular or net dipole if something is symmetrical with no lone pairs nonpolar molecule if something is nonsymmetrical, has lone pairs, or different exterior atoms polar molecule a conversion factor made with the moles of two different chemicals, using the coefficients of the balanced equation mole ratio our stoichiometry problems are going to be using what 3 units of measurement? mass, moles, particles/molecules when you have the exact amount of reactants to react completely with nothing leftover stoichiometric the reactant that can produce the least amount of product or limits how much product can be made. it's used up before the others limiting reactant the reactant(s) that is/are leftover after the limiting reactant is completely used up excess reactant the amount of product produced yield calculated mass of a product that would be obtained if all the limiting reactant were converted to product; what you calculate in limiting reactant problems theoretical yield the theoretical yield of something is dependent on what? only the amount of limiting reactant the mass of product obtained in a real experiment; number is given to you actual yield the actual yield of something is dependent on what? amount of limiting reactant and other factors the ratio of the amount of product actually made to the amount of product that could have been made under an ideal situation percent yield What's the percent yield formula actual yield / theoretical yield x 100 what is percent yield dependent on? NOT dependent on amount of limiting reactant or scale/size of the reaction are gases compressible or incompressible? compressible are solids/liquids compressible or incompressible? incompressible which have high densities which have low densities? gases or solids/liquids? gases have low, solids/liquids have high gases always mix _____ with anything and uniformly exert pressure in ____ directions completely; all as gravity increases, the pressure of solids/liquids ______ increases how we explain gas particles kinetic molecular theory what are the 5 points of the kinetic molecular theory for GASES? 1) gases have no volume 2) gases are in rapid, random motion with each other 3) all gas particle collisions are elastic (no loss of energy 4) particles have negligible attractive or repulsive forces between them 5) at the same temp, all gases have the same average kinetic energy when there is more gas pressure outside than inside a container implode when there is more gas pressure inside than outside a container explode the mixing of gases from a high to low concentration diffusion gas moving through a hole effusion the velocity of gas particles is ______ proportional to their mass inversely what is the constant measurement of atmospheric pressure 760 mmHg putting a tube of gas upside down into a bowl of the same gas and realizing that a little bit of the gas stays inside because of the surrounding pressure barometer force applied per unit area pressure formula for pressure pressure = force / area the average pressure of the earth's atmosphere at sea level; the standard pressure atm what else equals 1 atm? 760 mmHg, 101.3 kPa, 760 torr pressure is inversely proportional to volume boyle's law volume is directly proportional to temperature charles's law pressure is directly proportional to temperature gay-lussac's law what law is this: P1V1 = P2V2 boyle's law what law is this: V1 / T1 = V2 / T2 Charles's law what law is this: P1 / T1 = P2 / T2 gay-lussac's law What's the combined gas law formula? P1V1 / T1 = P2V2 / T2 temperature must always be in what unit? kelvin what's the stp? 273 K; 760 mmHg equal volumes of gases at the same pressure and temperature contain equal numbers of moles avogadro's law what law is this: v1 / n1 = v2 / n2 avogadro's law one mole of ___ gas will have the same volume at stp any what's the difference between a real gas and an ideal gas according to the kinetic molecular theory? ideal gas has no volume and they don't interact; real gases have a small volume and are weakly attracted to each other at low temperatures and high pressures the volume of a gas is related to pressure, temperature, and the number of moles ideal gas law what's the only thing that volume is inversely proportional to? pressure what's the ideal gas law formula PV = nRT what is the gas constant (R)? 0.0821 Latm/molK the total pressure of gas in a system is the sum of the partial pressures of each component gas dalton's law in dalton's law (partial pressures), what is constant in each gas component? r, t, v What is Dalton's law formula Ptot = n1RT / V + n2RT / V + n3RT / V..... the volume of one mole of a gas at STP molar volume What's the conversion factor of molar volume? 22.4 L/ mole What are the 3 points of the kinetic molecular theory for SOLIDS/LIQUIDS? 1) particles have significant attractions to one another 2) they occupy a significant part of the volume 3) they are not in random motion what are the types of intermolecular forces from weakest to strongest? london dispersion, dipole dipole, hydrogen bonding interactions between the molecules of a compound intermolecular forces electrostatic forces between molecules that result from instantaneous (temporary) dipoles london dispersion forces present in all molecular compounds london dispersion forces the _____ the molar mass, the more likely the compound will be a liquid or solid higher the attraction of the negative end of a polar molecule with the positive end of another polar molecule dipole dipole attraction for 2 molecules w/ similar size, a _____ one will be more likely to be a solid or liquid polar how do you know if something is dipole-dipole? if it's polar in a hydrogen bond, H has to bond with what why? F, O, or N; because they're the most electronegative elements and their bonds are very polar in molecules with a NH, FH, or OH bond, the interaction of a hydrogen atom from one molecule with the N,O,or F of another hydrogen bond hydrogen bonds have a comparably ___ boiling point high what are some real life examples of hydrogen bonds? hold together the bases of dna, NH bonds and O atoms are in amino acids As temperature increases, so does the ____ of a particle energy What happens when you raise the temperature on a solid so high and it has too much energy to stay a solid? it melts What are the 2 types of solids? amorphous and crystalline solids with no defined shape or melting point amorphous solids examples of amorphous solids glass, rubber, plastic solid where the atoms, molecules, or ions are arranged in a regular, symmetric structure called a crystal lattice; have a definite melting point crystalline solids examples of crystalline solids salt, sugar, quartz, ice, diamond crystalline solid in which ions make up the crystal lattice; very hard and brittle ionic solid ionic solids have very ___ melting points high salt is what kind of solid? crystalline and ionic crystalline solid in which molecules make up the crystal lattice molecular solid examples of molecular solids sugar, ice, dry ice, iodine molecular solids have very ___ melting points low crystalline solid in which metal cations make up the crystal lattice, and electrons move freely (makes them good conductors) metallic solid metallic solids have a _____ melting point wide range the force that causes the surface of a liquid to contract surface tension the resistance of a liquid to flow viscosity what causes a high viscosity? strong intermolecular forces and complex molecules that get tangled together change from a liquid to gas vaporization vaporization at the boiling point or at a higher temperature boiling vaporization at temperatures lower than the boiling point evaporation When do liquids evaporate more easily? high temps, low pressures, weak intermolecular forces, high vapor pressure, nonpolar the change from gas to liquid condensation the pressure exerted by a vapor above a liquid (at a given temp) vapor pressure low temp = ____ vapor pressure; high temp = _____ vapor pressure low; high the change from solid directly to a gas sublimation temperature at which the vapor pressure of a liquid equals the atmospheric pressure (1 atm) boiling point the higher the molar mass, the ______ the boiling point higher the stronger the attractions, the ______ the boiling point higher the amount of heat (cal or J) required to melt one gram of a substance heat of fusion what's the heat of fusion formula? heat (Q) = mass (m) x heat of fusion (Hf) what's the difference between heat of fusion/vaporization and specific heat? in heat of fusion there is no change in temperature the amount of heat required to vaporize one gram of a substance heat of vaporization what's the heat of vaporization formula? heat (Q) = mass (m) x heat of vaporization (Hv) the quantity of heat required to raise a gram of any substance by 1 degree Celsius. specific heat specific heat of water 4.184 J/g deg C specific heat equation Q = mC(change in T) what does not need to be in Kelvin? specific heat What is the Bronsted-Lowry definition of an acid? Substance that donates protons (H+) to other substances. What is the Bronsted-Lowry definition of a base? Substance that can accept protons from other substances. How do acids react in aqueous solutions? Acids transfer H+ to water to form a hydronium ion, H3O+. How do bases react in aqueous solutions? Water transfers H+ to the base to form a hydroxide ion, OH-. What is the definition of pH? -log[H3O+] where [H3O+] is the concentration of protons in a solution. What is the definition of pOH? -log[OH-] where [OH-] is the concentration of hydroxide ions in a solution. What is the definition of a buffer? Chemical systems that strive to maintain pH of a solution in a limited range. How does adding acid affect a buffer solution? It shifts the reaction to the reactants side which causes acid to be removed from the solution. How does the addition of a base affect a buffer solution? It shifts the reaction to the products side which causes more acid to be added to the solution. What happens when a carboxylic acid reacts with a strong base? The carboxylic acid is neutralized rapidly and quantitavely. How do you name cyclic carboxylic acids? Give the lowest number to the COOH group. Identify the name of the ring followed by carboxylic acid, dicarboxylic acid, etc. How do you name aromatic carboxylic acids? The ring carbon attached to the carboxyl group is the #1 position. Substituted benzoic acids are named with benzoic acid as the parent name. What are some physical properties of carboxylic acids? -Polar compounds. -Higher boiling point than other organic compounds. -More soluble in water than alcohols, ketones, aldehydes, or ethers due to their strong association with water molecules. -As size of the carbon chain increases, solubility decreases. -Smaller aliphatic carboxylic acids have very sharp odors. What are some physical properties of Esters? -Because of C=O group, Esters can act as hydrogen bond acceptors. -More soluble in water than corresponding alkanes. -Boiling points are lower because they can't form inter molecular hydrogen bonds between ester molecules. What is the functional group for a carboxylic acid? O II R-C-OH What is the functional group for an Ester? O II R-C-OCH3 How do you name Esters? The alkyl group bonded to the oxygen is named first followed by the name of the acid. The suffix of the parent acid is replaced with -oate. What is the definition of esterification? Reaction is carboxylic acid with an excess of a low molecular weight alcohol in the presence of a catalytic amount of mineral acid. What is the definition of fischer esterification? The esterification of a carboxylic acid by heating it with an alcohol in the presence of a strong acid as the catalyst. Why does the hydrolysis of an ester occur? The products are acid salt and alcohol. Acids can't exist in basic conditions so product is salt of carboxylic acid using cation of base catalyst. Ester + Water ---- Carboxylic acid salt + Alcohol What is the definition of saponification? Cleavage of triglycerides (esters) with excess base. What are some characteristics of soaps? In aqueous solutions, molecules orient themselves into micelles. The hydrocarbon tail is pointed inward. Carboxylate is pointed outward toward the surrounding water. What are some characteristics of synthetic detergents? Clean like soap but don't form soap scum. They are chemically similar to soap but with an important difference. What is the functional group for the Acid Anhydride? O O II II R-C-O-C-R How do you classify a Primary amine? CH3-NH2 How do you classify a secondary amine? CH3-NH-CH3 How do you classify a tertiary amine? CH3 I CH3-N-CH3 What is the definition of an aliphatic amine? Amine in which the nitrogen is bonded only to alkyl groups. What is the definition of an aromatic amine? Amine in which nitrogen is bonded to one or more aromatic rings. How do you name amines? The longest chain containing amino group is named for alkyl group(s) attached to the nitrogen followed by the word amine. For secondary and tertiary amines: -The largest group attached to the nitrogen is the parent amine. Smaller groups are names as substituents and labeled with "N". What are some properties of amines? -polar compounds -very pungent smell -Primary and secondary amines form hydrogen bonds to themselves but not as strongly as alcohols. -Tertiary amines cannot form hydrogen bonds to themselves because no hydrogen is present on the nitrogen atom. -low molecular weight amines are water soluble. -Because of hydrogen bonding, amines have higher boiling points than hydrocarbons but less than alcohols as they form weaker hydrogen bonds than alcohols. What are some properties of amides? -Hydrogen bond acceptors due to C=O group. -More soluble in water than corresponding alkanes. -Amides are not bases. -Boiling points are higher than corresponding alkanes because they're polar molecules and hydrogen bond to amide molecules. How do you name amides? The suffix of the parent acid is replaced with -amide. If nitrogen is bonded to an alkyl group, group is named and its location on the nitrogen is located by N. 2 alkyl groups are indicated by N,N-Di-. What is the aldehyde functional group? O II R-C-H What is the ketone functional group? O II R-C-R What is the primary amine functional group? R-NH2 What is the secondary amine functional group? R-NH-R What is the tertiary amine functional group? R I R-N-R What is the amide functional group? O II R-C-NH2 What is the ether functional group? R-O-R What is the alcohol functional group? R I R-C-OH I R