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CHEM 121 FINAL EXAM 2025-
QUESTIONS AND ANSWERS PRACTICE
GRADED A+
What are the different levels of energy? 1s < 2s < 2p < 3s < 3p < 4s < 3d < 4p < 5s < 4d < 5p < 6s How do you convert Celsius to Fahrenheit? Fahrenheit = (Celsius x 9/5) + 32 How do you convert Fahrenheit to Celsius? Celsius = (Fahrenheit - 32) x 5/ How do you convert Celsius to Kelvin? Kelvin = Celsius + 273. How do you convert Kelvin to Celsius? Celsius = Kelvin - 273. How do you convert Fahrenheit to Kelvin? Kelvin = (Fahrenheit + 459.67) x 5/
How do you convert Kelvin to Fahrenheit? Fahrenheit = (Kelvin x 9/5) - 459. What is Hess's Law? When reactants are converted to products, the enthalpy of the reaction is the same, no matter if it occurs in one step, or a series of steps. What is the Pauli Exclusion Principle? Each electron has a set of 4 numbers, called quantum numbers (q.n.'s.) that specify it completely. No two electrons in the same atom can have the same 4 q.n.'s. The primary quantum number n tells you which of the main energy levels you are in. What is the principle of quantum number n? Describes the distance of the orbital from the nucleus. The larger the value the larger the distance of the electron. What is the magnetic quantum number ml? Tells us the 3D orientation of the orbital in space. What is the electron spin quantum number ms?
Those who do not normally look to bond together from number of valence electrons. What is a hybrid state? Moving the composition of electrons throughout the s, p and d levels of electrons. What are the 3 different kinds of hybridization? sp: 2 s --- 1s 1p sp2: 2s 1 p --- 1s 2p sp3: 2s 2p --- 1s 3p What is the purpose of hybridization? To stabilize the atom. What can carbon bond with as far as hybridization? sp, sp2, sp Which equation relates pressure, temperature, volume and number of moles of gas? PV = nRT P = pressure (atms)
V = volume (Liters) n = number of moles R = constant, 8.314 J K^-1 mol ^- T = temperature (ALWAYS IN Kelvin) What is Boyles Law? Relates the pressure of gases to volume. What is Charles Law? Relates temperature and volume. What is Avogrados law? Relates the number of moles. What is Avogadros number? 6.022 x 10 ^ 23 What is formal charge? Natural valence subtract (-) current valence on the lewis structure = Formal Charge
What are the prefixes for non metal compounds? 1 = mono 2 = di 3 = tri 4 = tetr(a) 5 = pent(a) 6 = hex(a) 7 = hept(a) How do you name a nonmetal compound? Name the first compound first and second compound second. The second compound has it's number in the beginning. How do you name compounds? Write the element farther to the left of the periodic table first. Then class the compound by it's family. EX. Cl = chloride. What are some common conversions? mega = 10^ kilo = 10^ Hecto = 10^ Deka = 10 deci = 10^- centi = 10^-
Milli = 10^- Micro = 10^- What is the natural valence? The group number will indicate an element's natural valence. What does it mean do have open surroundings? One that can exchange energy to the surroundings freely What does it mean to have closed surroundings? Allows energy to escape but not mass What does it mean to have isolated surroundings? Allows nothing to transfer between the system and the surroundings What are the different bonds of electronegativity? 0 = pure covalent 2 or over 2 = pure ionic 0 < and >2 = polar covalent
What is a non electrolyte? A substance that does not readily ionize when dissolved or melted. A poor conductor of electricity. What is an electrolyte? A compound that conducts electricity by changing into ions when melted or dissolved into a solution. Ex. Sodium Chloride. kinetic molecular theory all matter is made of tiny particles that are constantly moving fundamental particle take a macroscopic object and divide it repeatedly. Eventually you have a particle, which, if further divided is no longer the original substance. This smallest piece of the substance is called... h2o molecule the fundamental particle of water is what? atom the basic unit of a chemical element
molecule two or more atoms (same or different) chemically bound element fundamental particle contains only one kind of atom compound two or more different kinds of atoms chemically bound the same in a pure substance, all the fundamental particles are what? solution mixture that is uniform throughout density = mass / volume atomic number
properties of metals good conductors of heat and electricity, malleable, ductile, often shiny, tend to lose electrons in chemical change properties of non metals poor conductors of heat and electricity, not ductile, not malleable, gain electrons in chemical change avagadros number 6.022 x 10^ ionic bond bond between a nonmetal and a metal covalent bond bond between 2 or more nonmetals naming covalent compounds first element is given its element name, second suffix replaced by "ide", USE GREEK PREFIXES
naming ionic compounds name the metal, if the metal has an uncommon charge, indicate the charge with roman numerals, change nonmetal suffix to "ide", if polyatomic ion just name them properties of ionic compounds crystalline, hard, brittle, high melt point, insulators as solid, but conductors in solution or when melted percent composition mass of element / total mass of compound x 100 ionic which type of compound completely dissociates in water to form electrolytes? empirical formula uses the simplest integers to represent the ratio of atoms in a compound molecular formula shows the actual number of atoms of each element in one molecule of a compound
water and a salt the products of an acid-base reaction will always be what? molarity moles of solute per liter of solution (M= mol/L) increases In dilution, the number of moles does not change, but the volume what? limiting reactant this is the reactant in a chemical reaction that limits the amount of product that can be formed reactant in excess reactant in which some of it will remain at the end of the reaction theoretical yield max amount of product that can be obtained, that YOU calculate
actual yield amount of product that we obtain in an experiment percent yield % = actual / theoretical x 100 heat the amount of energy that can be transferred from one object to another due to a temperature difference temperature measure of the average kinetic energy of particles exothermic system releases heat endothermic system absorbs heat titrations
this is used to find energy in chemical reactions, coffee cup/bomb hess's law of heat summation If the equation for a reaction can be written as 2 or more thermochemical equations, then the enthalpy change for the reaction equals the sum of the enthalpies of those equations standard enthalpy of formation = SUM deltaHf of products - SUM deltaHf of reactants bomb calorimeter q = Ccal x deltaT heat capacity C = m x c (m= mass c= specific heat) light a form of electromagnetic radiation, composed of two perpendicular oscillating waves
speed of light 3.00 x 10^8 m/s wavelength distance between two peaks of a wave (lambda) amplitude height of the wave frequency (nu), number of waves passing per unit of time (units: Hertz) frequency equation v= speed / wavelength energy of a photon equation E= hv, E= hc/lambda planck's constant
