Straighterline CHEM101 Final exam with 100% correct answers.docx, Exams of Biology

Download Straighterline CHEM101 Final exam with 100% correct answers.docx and more Exams Biology in PDF only on Docsity! Straighterline CHEM101 Final exam with 100% correct answers total number of neutrons and protons in an atom; # protons + # electrons - answer Mass Number Most nonmetallic elements are found in which block of the periodic table? - answer p Ernest Rutherford disproved J.J. Thomson's plum- pudding model of the atom by showing that... - answer Positive matter is concentrated in the central core Plants use up copious amounts of which alkali metal, preventing most of it from being washed out to sea? - answer Potassium What is the ratio of reactants and products in the chemical equation? __NaOH + __H2SO4 --> __Na2SO4 + __H2O - answer 2:1:1:2 What is Avogadro's number? - answer the number of ATOMS in 12g of Carbon-12 1 g = 6.022 × 1023 amu What is the reducing agent in the following equation? Mg(s) + 2HCl(aq) -> MgCl2(aq) + H2(g) - answer Mg Which arrangement accurately describes the standard entropy values at different phases? - answer (s) < (l) < (g) What are the most stable isotopes? - answer 2, 8, 20, 50, 82 or 126 protons What element has been oxidized and what element has been reduced? fixed composition and differs from a mixture (every sample has same properties and composition) - answer Pure Substance molecule with a charge contain more than 1 atom chemically bonded together - answer Polyatomic Ion atoms with charge formed by loss or gain of an electron - answer ions positive ion, may have roman numeral - answer Cation negative ion, element ends in -ide - answer Anion atom of an element that has a different mass because of a different number of neutrons, but same atomic number - answer isotope total number of protons in an atom; also indicates number of electrons - answer Atomic Number additional reactant that increases the rate of a reaction with a lower activation energy - answer Catalyst What 4 factors impact the rate of a reaction? - answer Surface area Concentration Temperature Catalyst A reaction that RELEASES energy in the form of heat - answer exothermic reaction A reaction that ABSORBS energy in the form of heat - answer endothermic reaction How many particles/atoms/molecules are in a mole? - answer 6.022 x 10^23 particles Surface area impacts rate of reaction how? - answer Amount of area exposed for the reaction of a solid Concentration impacts rate of reaction how? - answer increase the # of reactants in the container, more collisions occur w/enough energy & proper orientation Temperature impacts rate of reaction how? - answer Higher temperature....more motion....more forceful or higher energy collisions pressure increases, volume decreases pV = constant or p1V1 = p2V2 - answer Boyle's Law Volume goes up, then temperature goes up, pressure remains the same V/T = constant or V1/T1 = V2/T2 - answer Charles' Law volume increases with number increases v/n - answer Avogadro's Law increase in temperature & increase in pressure p/T = constant or p1/T1 = p2/T2 - answer Guy- Lussac's Law PV = nRT - answer Ideal Gas Law When do you use the Ideal gas law? - answer when 3 variables are given in an question Fahrenheit to Celsius - answer C = (degrees F - 32) (5/9) Celsius to Fahrenheit - answer F = (degrees C + 32) (9/5) find density - answer d = m/v find volume - answer v = m/d find mass - answer m = dv doesn't require explicit measurement - answer Qualitative Property state of matter changes, but identity of matter doesn't change - answer physical change substance is transformed into different substance(s) - answer chemical change measured value depends on amount of matter; values of same extensive properties can be added Ex: mass, length - answer extensive property value does NOT depend on matter; cannot be added Ex: density, temperature - answer intensive property how close a measurement is to the true value - answer accuracy how close a group of measurements are to each other - answer precision meausured numbers - answer inexact numbers numbers obtained by counting or are part of a definition - answer exact numbers series of unit conversions used in solution of multi- step problem - answer dimensional analysis emission and transmission of energy through space in the form of waves - answer Radiation mass of an electron - answer = charge / charge or mass Positively charged particles (helium nuclei) deflected AWAY from the positively charged plate. - answer alpha rays electrons deflected away from the NEGATIVELY charged plate - answer beta rays high-energy, no charge, unaffected by external electric or magnetic fields - answer gamma rays Electrons are spread throughout the atom, like blueberries in a muffin - answer Thomson's Plum Pudding Model horizontal rows - answer periods vertical columns - answer groups/families good conductor of heat and electricity - answer metal poor conductor of heat and electricity - answer Nonmetal polyatomic anions that contain 1+ oxygen atoms Ex: chlorate (CIO3-), nitrate (NO3-), sulfate (SO4 2-) - answer oxoanions ionic compounds that also contain water molecules Ex: BaCl2 x H2O (barium chloride dihydrate) LiCl x H2O (lithium chloride monohydrate) MgSO4 x 7H2O (magnesium sulfate heptahydrate) Sr(NO3)2 x 4H2O (strontium nitrate tetrahydrate) - answer hydrates compound without water - answer anhydrous produces H+ ions when dissolved in water - answer acids ionize to produce hydrogen ions and the corresponding oxoanions - answer oxoacids do not contain carbon - answer inorganic compounds contain carbon and hydrogen - answer organic compounds simplest organic compounds - answer Hydrocarbons Hydrocarbons that contain only single bonds - answer alkanes a chemical formula showing the ratio of elements in a compound rather than the total number of atoms - answer empirical formula formed by Dalton states that all matter is made of tiny particles called atoms - answer atomic theory any sample of a given compound will always contain the same elements in the same mass ratio - answer law of definite proportions if two elements can form more than one compound with one another, the mass ratio of one will be related to the mass ratio of the other by a small whole number - answer law of multiple proportions matter can be neither created nor destroyed - answer law of conservation of mass consists of just 1 atom - answer monatomic/atomic ion consists of cations and anions in an electrically neutral combination - answer ionic compound electrically neutral group of 2+ atoms - answer Molecule A molecule consisting of only two atoms - answer diatomic molecule diatomic molecule, just 1 kind of atom - answer homonuclear diatomic molecule, 2 kinds of atoms - answer heteronuclear molecules containing more than two atoms - answer polyatomic molecule A homogeneous mixture of two or more substances - answer solution the substance present in the largest amount - answer solvent any substance present in a smaller amount - answer solute a substance that dissolves in water to yield a solution that conducts electricity - answer electrolyte a substance that dissolves in water to yield a solution that does not conduct electricity - answer nonelectrolyte the process by which an ionic compound, upon dissolution, breaks apart into its constituent ions - answer Dissociation An electrolyte that dissociates completely - answer strong electrolyte a compound that produces ions upon dissolving but exists in solution predominantly as molecules that are not ionized - answer weak electrolyte 7 strong acids - answer HCl HBr HI HNO3 HClO3 HClO4 H2SO4 or HSO4- maximum amount of solute that will dissolve in a given quantity of solvent at a specific temperature - answer Solubility HCl HBr HI HNO3 HClO3 HClO4 H2SO4 - answer strong acids LiOH NaOH KOH RbOH CsOH Ca(OH)2 Sr(OH)2 Ba(OH)2 - answer strong bases chemical reaction in which electrons are transferred from one reactant to another - answer redox/reduction reaction loses electrons - answer oxidized gains electrons - answer reduced The oxidation number of any element, in its elemental form, is... - answer 0 Fluorine oxidation # - answer -1 group 1A oxidation # - answer +1 gets oxidized - answer reducing agent relates the absorbance of a solution to its concentration and the path length through which the light passes - answer Beer-Lambert law involves an acid-base reaction Typically, a solution of known concentration (a standard solution) is added gradually to a solution of unknown concentration with the goal of determining the unknown concentration. - answer titration The point at which the reaction in the titration is complete - answer equivalence point a substance that changes color at or near the equivalence point of a titration - answer indicator The point at which the indicator changes color - answer endpoint volume of concentrated solution is diluted - answer Mc × Lc = Md × Ld - answer moles of solute before dilution = moles of solute after dilution - answer Mc × mLc = Md × mLd In absorption spectrophotometry, transmittance (T) is equal to the ratio of transmitted light (I) to incident light (I0). - answer T = I / I0 Absorbance (A) is equal to minus the log of transmittance. - answer A = -logT = -logI/I0 The Beer-Lambert law is used to determine concentration from absorbance (A), molar absorptivity (e), and path length (b) through the sample. - answer A = etc the capacity to do work or transfer heat - answer Energy energy of motion Ek = 1/2 mu^2 m=mass u=velocity - answer kinetic energy energy associated with the random motion of atoms and molecules - answer thermal energy energy possessed by an object by virtue of its position - answer potential energy energy stored within the structural units (molecules or polyatomic ions) of chemical substances - answer chemical energy potential energy that results from the interaction of charged particles - answer electrostatic energy When energy of one form disappears, the same amount of energy must appear in another form or forms - answer Law of Conservation of Energy the study of heat changes in chemical reactions - answer Thermochemistry SI unit of energy - answer joule (J) SI unit for temperature - answer Kelvin SI unit for mass - answer kilogram heat released or absorbed at constant volume formula - answer (q)v = ^U heat released or absorbed at constant pressure - answer (q)p = ^U + P^V change in enthalpy formula - answer ^H = ^U + P^V The distance between 2 crests of a wave - answer Wavelength The number of waves that pass a point per unit time - answer Frequency the distance from the midpoint to the crest (or trough) of the wave - answer Amplitude have both electric and magnetic components that are both mutually perpendicular and in phase - answer electromagnetic waves Max Planck said energy is composed of this particle - answer quanta a quantum of light - answer photon the lowest possible energy state for an atom - answer ground state any energy level higher than the ground state - answer excited state a point at which a standing wave has zero amplitude - answer node the wavelength associated with a particle of very small mass - answer de Broglie wavelength - answer 1s22s22p63s23p5, p-block, main group - answer 1s22s22p63s23p64s23d104p65s1, s- block, main group - answer 1s22s22p63s23p64s23d2, d-block, transition metal atomic radius trends - answer L to R = decreasing T to B = increasing Be shiny, lustrous, and malleable Be good conductors of both heat and electricity Have low ionization energies (so they commonly form cations) Form ionic compounds with chlorine (metal chlorides) Form basic, ionic compounds with oxygen (metal oxides) - answer metals Vary in color and lack the shiny appearance associated with metals Be brittle, rather than malleable Be poor conductors of both heat and electricity Form acidic, molecular compounds with oxygen Have high electron affinities (so they commonly form anions) - answer Nonmetals - low ionization energies - easy to become M+ ions - very reactive - highly reactive with water, O, and acids to produce H gas and metal hydroxides - ns1 - answer Group 1A characteristics - both 1st and 2nd ionization energies decrease Lewis dot symbol is same as traditional group number for these elements - answer main group elements number of dots in the Lewis dot symbol is the number of electrons that are lost when the atom forms a cation that is isoelectronic with the preceding noble gas - answer main group metals one pair of shared electrons - answer single bond share more than 1 pair (double bond, triple bond) - answer multiple bonds unequal sharing of electrons - answer polar bonds - answer densities of gases are much smaller than those of liquids and solids and are highly variable depending on temperature and pressure gases exert... - answer pressure net pull inward on molecules at the surface of a liquid - answer surface tension attractive forces between molecules within a substance - answer cohesion attractive forces between molecules in a substance and their container - answer adhesion solid to liquid - answer melting/fusion solid to gas - answer sublimation liquid to solid - answer freezing Liquid to gas - answer Vaporization Gas to liquid - answer condensation gas to solid - answer deposition made up of monomers - answer polymer no resistance to electric flow - answer Superconductor a solution that contains the maximum amount of dissolved solute - answer saturated solution A solution that contains less than the maximum amount of solute - answer unsaturated solution contains more dissolved solute than specified - answer supersaturated solution 2 liquids soluble in each other - answer miscible moles of solute/kg of solvent - answer molality mass of solute/mass of solution x 100 - answer percent by mass increasing temp. ______ solubility of most solids in water and ______ solubility of most gases in water - answer increases, decreases dispersion of particles of 1 substance in another substance - answer colloid water loving - answer hydrophilic electrons can be readily promoted to the conduction band, where they are free to move through the substance - answer conductor the energy gap between the valence band and the conduction band is so large that electrons cannot be promoted into the conduction band - answer insulator substances that normally are not conductors but will conduct electricity at elevated temperatures or when combined with a small amount of certain other elements - answer semiconductor most reactive metals, oxidation state of +1 - answer alkali metals somewhat less reactive than alkali metals, oxidation state of +2 - answer alkaline earth metals - answer elemental N (N2) contains a triple bond and is very stable study of carbon-based substances - answer organic chemistry contain a benzene ring - answer Aromatic compounds do not contain benzene rings - answer aliphatic compounds contains both carboxyl group and amino group - answer amino acid polymers of sugars - answer Polysaccharides Amount of area exposed for the reaction of a solid. - answer Surface area impacts rate of reaction how? increase the # of reactants in the container, more collisions occur w/enough energy & proper orientation. - answer Concentration impacts rate of reaction how? Higher temperature....more motion....more forceful or higher energy collisions. - answer Temperature impacts rate of reaction how? All gases behave the same way physically, especially at high or low temperatures - answer What is ideal gas behaviour? mass changing direction or speed = mass x acceleration - answer force what bond is non-metal to non-metal, uses prefixes? - answer covalent bonds What bond is metal & non-metal or metal & polyatomic - answer ionic bonds 1. Vapor-pressure lowering 2. Boiling-point elevation 3. Freezing-point depression 4. Osmotic pressure - answer Name the four colligative properties used to determine the relative mass of an element from its isotopic composition - answer What is mass spectrometry used for? Electrons occupy the space outside of the nucleus - answer Where is an electron found?