Prepare for the New York Chemistry Regents exam with these practice questions and answers. This comprehensive guide covers all topics tested on the NYS Chemistry Regents.
Q: Protons
Answer: Positively charged
Q: Neutrons
Answer: Negatively charged
Q: Electrons
Answer: Small and negatively charged
Q: nucleus
Answer: protons and neutrons are in here
Q: orbitals
Answer: electrons in clouds around the nucleus
Q: mass number
Answer: equal to an atom’s protons and neutrons added together
Q: atomic number
Answer: amount of protons in the nucleus of an atom
Q: number of neutrons
Answer: atomic mass – atomic number
Q: isotopes
Answer: atoms with equal numbers of protons, but differ in their neutron amounts
Q: Cations
Answer: positive ions and form when a neutral atom loses electronssmaller than parent atom
Q: Anions
Answer: negative ions and form when a neutral atom gains electronsLarger than parent atom
Q: Ernest Rutherford
Answer: Gold foil experiment- atom is mostly empty space with a small, dense, positively charged nucleus
Q: J.J. Thompson
Answer: discovered electron, developed the “plum-pudding” model of the atom
Q: Dalton’s model
Answer: solid sphere of matter that was uniform throughout the entire atom
Q: Bohr’s model
Answer: placed electrons in “planet like” orbits around the atom’s nucleus
Q: Wave-mechanical model (current)
Answer: electrons in “clouds” orbiting the nucleus
Q: USE THE
Answer: REFERENCE TABLES
Q: STP
Answer: Standard Temperature and Pressure (273K and 1 atm)
Q: Ground/Excited stateBright line spectra
Answer: Electrons emit energy when jumping from higher energy levels to lower energy levels.BLS- energy as light produced when the electrons go from a higher energy level to a lower one
Q: elements
Answer: pure substances composed of only one atom
Q: Binary compounds
Answer: substances made up of only 2 kinds of atoms
Q: Diatomic molecules
Answer: elements that form 2 atom molecules in their natural form at STP (O2)
Q: Significant Figures
Answer: PacificIf the decimal point is present, start counting digits from the Pacific (left) side, starting with the first non-zero digit0.00310 (3 sig figs)AtlanticIf the decimal point is absent, start counting digits from the Atlantic (right) side, starting with the first non-zero digit31,400 (3 sig figs)
Q: Solutions
Answer: homologous mixtures
Q: heterogeneous mixture
Answer: mixtures that aren’t uniform throughout
Q: SoluteSolvent
Answer: substance being dissolvedsubstance that dissolves the solvent
Q: naming isotopes
Answer: C-14 or Carbon-14
Q: electron configuration
Answer: distribution of electrons in an atom
Q: electron configuration on reference tables
Answer: on the bottom of every element’s box
Q: Mole-Triangle Diagram
Answer: a way of drawing electron configuration of an atom (not needed for regents chem)
Q: Orbital rotation (not needed for regents chem)
Answer: groups of atoms with an overall charge
Q: Polyatomic Ion (table E)
Answer: written in front of the formulas of reactants and products in chemical equations. They give us the ratios of reactants and products in a balanced chemical equation.
Q: Coefficients
Answer: written so that the charges of cations and anions neutralize each other
Q: chemical formulas
Answer: write the name of the cation first, followed by the name of the anion the name ending in “-ide”ex: KCl (potassium chloride)
Q: naming binary compounds
Answer: keep the name of the polyatomic ion the same as it is written in Table Eex: NH4Cl (ammonium chloride)
Q: naming compounds w/ polyatomic ions
Answer: don’t form new substancesmerely change appearance of the original material
Q: Physical Changes
Answer: form a new substance
Q: chemical changes
Answer: on left side of reactionon right side of reaction
Q: Reactantsproducts
Answer: absorb heatthe energy value is on the left side of the reaction in a forward reaction
Q: Endothermic reaction
Answer: release energyenergy value is on the right side of the reaction in a forward reaction
Q: Exothermic Reaction
Answer: can only be changed when balancing reactions
Q: coefficients in reactions
Answer: occurs when 2 or more reactants combine to form a single productex: 2H2(g) + O2(g) -> 2H2O(g)
Q: synthesis reaction
Answer: occurs when a single reactant forms 2 or more productsex: CaCO3(s) -> CaO(s) + CO2(g)
Q: Decomposition reaction
Answer: occurs when 1 element replaces another element in a compoundex: Mg + 2HCl -> MgCl2 + H2
Q: Single replacement reaction
Answer: occurs when 2 compounds react to form 2 new compoundsex: AgNO3 + KCl -> AgCl + KNO3
Q: Double replacement reaction
Answer: The masses of the reactants in a chemical equation is always equal to the masses of the products
Q: Law of Conservation of Mass
Answer: the gfm of a substance is the sum of the atomic masses of all of the atoms in itex: H2SO4 = 982 x 1 = 2 (H)1 x 32 = 32 (S)4 x 16 = 64 (O)64 + 32 + 2 = 98
Q: GFM (gram-formula mass)
Answer: formula is on Table T
Q: percent composition
Answer: 6.02 x 10^23amount of particles in 1 mole of a substance
Q: Avogadro’s Number
Answer: held rigidly together
Q: solid particles
Answer: have a definite shape and volume
Q: solids
Answer: closely spaced particles that slide easily past each other
Q: liquids (particles)
Answer: have no definite shapedefinite volume
Q: liquids
Answer: widely spaced particles that are in random motion
Q: Gases (particles)
Answer: easily compressedno definite shapeno definite volume
Q: Gases
Answer: solid -> gas
Q: Heating/cooling curves
Answer: K= C + 273
Q: sublimation
Answer: q=mc∆tq=heat absorbed or released (joules)m=mass of substance in gramsc=specific heat capacity of substance (J/g x C)∆t= change in temperature (celsius)
Q: kelvin -> celsius
Answer: the heat absorbed or released when 1 gram of a substance changes between solid and liquid phases
Q: Heat of reaction
Answer: the heat absorbed or released when 1 gram of a substance changes between liquid and gas phases
Q: Heat of fusion
Answer: ^/v
Q: heat of vaporization
Answer: ^/^
Q: pressure/volume (gas)
Answer: ^/^
Q: pressure/temperature (gas)
Answer: always use Kelvin for temperature
Q: temperature/volume (gas)
Answer: particles have volume and are attracted to one anothernot always like ideal gases
Q: combined gas law
Answer: a real gas behaves like an ideal gas at low pressure and high temperature
Q: Real gas
Answer: separates mixtures with different boiling points
Q: Ideal Gas
Answer: separates mixtures of solids and liquids
Q: distillation
Answer: used to separate mixtures of liquids and mixtures of gases
Q: filtration
Answer: states that the properties of elements are periodic functions of their atomic numbers(elements in the same group are the most similar)
Q: Chromatography
Answer: horizontal rows on the Periodic table
Q: periodic law
Answer: vertical rows on the periodic table
Q: periods
Answer: left of the “staircase” on the periodic tableabove the staircaseborder the staircase
Q: groups
Answer: metals:malleable,ductile,lustrous,good conductors of heat/electricity, low ionization energy and electronegativity, tend to form cationsnonmetals:brittle(when solid), mostly gases (at STP), dull, good insulators, high ionization energy and electronegativity, tend to form anions
Q: metalsnonmetalsmetalloids
Answer: inert and stable due to the fact that their valence level of electrons is completely filled
Q: memorize the chart
Answer: increases as you go up and to the right on the periodic table
Q: noble gases (group 18)
Answer: decrease left to right across a period due to increasing nuclear charge
Q: ionization energy
Answer: increase as you go down a group
Q: Atomic radii (period)
Answer: a measure of an element’s attraction for electrons
Q: Atomic radii (group)
Answer: increases as you go up and to the right on the periodic table
Q: electronegativity
Answer: group 1
Q: electronegativity on the periodic table
Answer: group 2
Q: alkali metals
Answer: group 17
Q: alkaline earth metals
Answer: group 18
Q: halogens
Answer: compare and look up the properties of specific elements
Q: noble gases
Answer: energy is released when a chemical bond formsthe more energy is released, the more stable the bond is
Q: table S
Answer: equal to the last digit of an element’s group number
Q: chemical bonds
Answer: draw one dot for each valence electron when drawing an element’s or ion’s Lewis Diagram
Q: number of valence electrons
Answer: the kernel of an atom includes everything in an atom except the atom’s valence electrons
Q: Lewis Diagram
Answer: can be thought of as crystalline lattice of kernels surrounded by a “sea” of mobile valence electrons
Q: Kernel
Answer: atoms are most stable when they have 8 valence electrons (an octet) and tend to form ions to obtain such a configuration of electrons
Q: Metallic Bonds
Answer: form when two atoms share a pair of electrons2 nonmetals
Q: atomic stability
Answer: form when one atom transfers an electron to another atom when forming as bond with it1 metal and 1 nonmetal
Q: covalent bonds
Answer: form when 2 atoms of the same element bond togetherex:diatomic molecules
Q: ionic bonds
Answer: form when the electronegativity difference between 2 bonding atoms is between 0.4 and 1.7
Q: nonpolar covalent bonds
Answer: form when the electronegativity difference between 2 bonding atoms is greater than 1.7
Q: polar covalent bonds
Answer: substances containing mostly covalent bonds
Q: ionic bonds (electronegativities)
Answer: substances containing mostly ionic bonds
Q: molecular substances
Answer: ionic: hard, high melting and boiling points, conduct electricity when molten or aqueouscovalent (molecular):soft, low melting and boiling points, don’t conduct electricity (insulators)
Q: ionic compounds
Answer: form when hydrogen bonds with N, O, or Fgives compound unusually high melting and boiling points
Q: memorize this table (substances)
Answer: use to predict the solubilities of compounds
Q: hydrogen bonds
Answer: substances tend to be soluble in solvents with similar properties”like dissolves like”
Q: Table F
Answer: as temperature increases, solubility increases for most solids
Q: solubility
Answer: at low temperatures and high pressures, solubility increases for most gases
Q: temperature/solubility
Answer: used to determine if a solution is saturated, unsaturated, or super saturated
Q: temperature and pressure/solubility
Answer: a way to measure the concentration of a solutionequal to the number of moles in the solute/ number of moles in the solutionformula is on the back of the reference tables
Q: Table G (solubility curve)
Answer: = mass of part/mass of whole x 100
Q: Molarity
Answer: grams solute / grams of solution x 1,000,000
Q: Percent by mass
Answer: solutes increase the boiling points and decrease the melting points of solvents
Q: parts per million (ppm)
Answer: liquids boil when their vapor pressure is equal to the atmospheric pressureex: glass of water condenses with water on the outside of the glass
Q: solutes and solvents
Answer: the normal boiling point of a substance is the temperature in which it boils at 1 atm of pressuretable H
Q: liquids boiling
Answer: tend to react more slowly than ionic compounds
Q: normal boiling point
Answer: ^/^
Q: Covalently bonded substances
Answer: ^/^
Q: concentration/reaction rate
Answer: ^/^
Q: surface area/reaction rate
Answer: catalysts speed up reactions by lowering their activation energiesthey aren’t changed themselves -> can be reused
Q: pressure/reaction rate
Answer: ^/^
Q: catalysts/activation energy
Answer: + for endothermic reactions- for exothermic reactions
Q: temperature/reaction rate
Answer: equal at equilibrium
Q: potential energy diagrams
Answer: any reactant or product to a system at equilibrium will shift the equilibrium away from the added substance
Q: ∆H
Answer: any reactant or product from a system at equilibrium will shift the equilibrium toward the removed substance
Q: rates of forward and reverse reactions
Answer: shifted by an increase in temperature
Q: adding
Answer: shifted by a decrease in temperature
Q: removing
Answer: ^/v
Q: endothermic direction
Answer: v/^
Q: exothermic direction
Answer: catalysts have no effect at equilibriumonly reaches equilibrium quicker
Q: pressure/moles of gas
Answer: heat energy gained or lost in a system
Q: pressure/moles of gas
Answer: high in a highly unorganized systemex:gas
Q: catalysts at equilibrium
Answer: useNOT NEEDED FOR REGENTS CHEM
Q: Enthalpy (H)
Answer: loss of electrons by an atom or ionoxidation # increases as a resultelectrons are on the right side of the arrow
Q: Entropy (S)
Answer: gain of electrons by atom or ionoxidation # decreases as a resultelectrons are on the left side of the arrow
Q: For the hypothetical reactionwA + xB -> yC + zDNOT NEEDED FOR REGENTS CHEM
Answer: always involve change of electrons
Q: oxidation
Answer: LEO says GERLose Electrons OxidationGain Electrons Reduction
Q: reduction
Answer: by seeking an uncombined element on one side of a reaction that is in a compound on the other side
Q: Redox reactions
Answer: object being reducedobject being oxidized
Q: way to remember oxidation and reduction
Answer: produce electricity with a spontaneous redox reaction
Q: Identify redox reactions
Answer: usually the site of oxidation in an electrochemical cell diagram
Q: Oxidizing agentsReducing agents
Answer: I have AN OX and a RED CAToxidation at the anodereduction at the cathode
Q: Electrochemical cells
Answer: use an applied electrical current to force a non-spontaneous redox reaction to take place
Q: left electrode
Answer: electrolytic cells can be used for this
Q: ways to remember electrochemical cells
Answer: acids and bases are good electrolytesthey also conduct electricity well
Q: Electrolytic cells
Answer: taste sour
Q: metal plating
Answer: taste bitter
Q: Good electrolytes
Answer: used to find indicators (acids and bases turn a different color when combined with these)
Q: weak acids
Answer: <7
Q: weak bases
Answer: >7
Q: Table M
Answer: list names and formulas of common acids and bases
Q: pH acids
Answer: Any metal above H2 on this scale will react with acids to form hydrogen gas
Q: pH bases
Answer: “acids give off H+ or H3O+ ions in solution””bases give off OH- ions in a solution”
Q: Tables K & L
Answer: “Acids donate protons””Bases accept protons”
Q: Table J
Answer: acids and bases react with each other to form water and a salt
Q: Arrhenius says
Answer: controlled neutralization reactions used to find the concentration of an acid or base sampleformula on table T
Q: Brønsted says
Answer: all contain carbon
Q: neutralization
Answer: always has 4 bonds
Q: Titrations
Answer: have single bonds within them (alkanes)
Q: organic compounds
Answer: have double or triple bonds in them (alkenes and alkynes)
Q: carbon
Answer: ONLY contain carbon and hydrogen
Q: saturated hydrocarbons
Answer: homologous series of hydrocarbons’ formulas
Q: unsaturated hydrocarbons
Answer: functional groups on organic molecules are listed
Q: hydrocarbons
Answer: of organic compounds have different structural formulas but the same molecular formulas
Q: Table Q
Answer: number the parent carbon chain in an organic molecule from end closest to alkyl group(s)
Q: Table R
Answer: occur when a hydrocarbon reacts with oxygen to make CO2 and H2O
Q: structural isomers
Answer: occur when an alkane and a halogen(group 17) reacts so that one or more hydrogen atoms on the alkane are replaced with oxygen
Q: naming isomers
Answer: occur when an alkene or an alkyne combine with a halogen to create a halide
Q: combustion reactions
Answer: occurs when an organic acid and an ester react to make water and an ester
Q: Organic substitution reactions
Answer: occurs when an ester reacts with a base to form an alcohol and a soap
Q: Organic addition reaction
Answer: occurs when catalyzes a sugar (C6H12O6) to make carbon dioxide and ethanol
Q: esterification
Answer: long chains of repeating units called monomers
Q: saponification
Answer: forms polymers
Q: fermentation
Answer: occurs when unsaturated monomers join in a long polymer chain
Q: Polymers
Answer: occurs when monomers join to form a polymer by removing waterWATER IS A PRODUCT
Q: polymerization
Answer: starch, cellulose, proteins
Q: addition polymerization
Answer: plastics such as nylon, rayon, and polyester
Q: condensation polymerization
Answer: unstable atoms that are radioactive are called radioisotopes
Q: natural polymers
Answer: radioisotopes can decay by giving off any of the particles/emanations listed on table J
Q: synthetic polymers
Answer: Positively charged (+)Negatively charged (-)
Q: Table N
Answer: the sum of the mass numbers and atomic numbers must be equal on both sides of the reaction arrow for nuclear equations
Q: Table J (radioisotopes)
Answer: split heavy nuclei into smaller ones
Q: Alpha particlesBeta particles
Answer: occur when light nuclei combine to form a heavy nucleus and a LOT of energy
Q: sum of mass numbers
Answer: the half life of radioisotopes is the length of time it takes for one half of the atoms in a sample to radioactively decay
Q: Fission reactions
Answer: used to determine the ages of organic material up to 23,000 years old
Q: fusion reactions
Answer: used to determine the ages of rocks
Q: Table N (half-life)
Answer: used to treat thyroid disorders
Q: C-14
Answer: used to treat cancerous tumors
Q: U-238
Answer: used to kill bacteria on foods to slow the spoilage process
Q: I-131
Answer: disposal of radioactive waste is a problem associated with nuclear reactors
Q: Co-60
Answer: TABLES
Q: Radiation
Answer: if you dont know the answer, just take a guess, some chance of getting it correct is better than no chance at all
Q: nuclear reactors
Answer: you have 3 hours to take this test. USE IT
Q: REFERENCE
Answer: it can help make the question make more sense
Q: be sure to answer every question
Answer: the reference tables are there to help you
Q: Take your time
Answer: only change an answer if you find an obvious mistake
Q: try substituting words you dont know with a different word
Answer: they are mostly on Table T in the reference tables
Q: consider on every question if the answer is on the reference tables
Answer: it isn’t worth spending your brain power on a hard questionanother question on the test may be able to help you answer it
Q: your first choice is usually your best one
Answer: eat a good breakfast before as well
Q: even if you think you know the formula, look it up
Answer: a tired mind won’t work as sharply as a well rested mind!
Q: skip a question if it is giving you a hard timego back to it later
Answer: you’ve seen all of this stuff before!