New York State Regents Examinations Physical Setting / Chemistry (Regents Examination) Flashcards

24 sample cards from the Physical Setting / Chemistry (Regents Examination) deck

Sampled from the end of the deck, so these are different cards from the ones shown on the syllabus page.

1. How does a catalyst speed up a reaction?

   A catalyst provides an alternative reaction pathway with a lower activation energy, without being consumed in the reaction; it does not change ΔH.

2. What is dynamic equilibrium in a reversible reaction?

   The state in which the forward and reverse reactions occur at equal rates, so the concentrations of reactants and products remain constant (though the reactions continue).

3. State Le Chatelier's Principle.

   When a system at equilibrium is disturbed by a change in concentration, pressure, or temperature, the equilibrium shifts in the direction that relieves the stress.

4. For an equilibrium, what is the effect of increasing the concentration of a reactant?

   The equilibrium shifts to the right (toward products) to consume the added reactant and relieve the stress.

5. What is entropy?

   Entropy (S) is a measure of the disorder or randomness of a system; gases have more entropy than liquids, which have more than solids.

6. What two factors favor a spontaneous chemical reaction?

   Reactions tend to be spontaneous when they release energy (decreasing enthalpy, exothermic, −ΔH) and when they increase disorder (increasing entropy, +ΔS).

7. According to the Arrhenius theory, what defines an acid and a base?

   An Arrhenius acid produces hydrogen ions (H⁺ / H3O⁺) as the only positive ion in aqueous solution; an Arrhenius base produces hydroxide ions (OH⁻) as the only negative ion in solution.

8. According to the Brønsted-Lowry theory, what is an acid and a base?

   A Brønsted-Lowry acid is a proton (H⁺) donor; a Brønsted-Lowry base is a proton (H⁺) acceptor.

9. What does the pH scale measure, and what pH values are acidic, neutral, and basic?

   pH measures the hydrogen-ion concentration of a solution. pH < 7 is acidic, pH = 7 is neutral, and pH > 7 is basic. Each unit change is a tenfold change in H⁺ concentration.

10. What is a neutralization reaction and what are its products?

    A neutralization reaction is between an acid and a base, producing a salt and water (acid + base → salt + water).

11. In oxidation-reduction reactions, define oxidation and reduction in terms of electrons.

    Oxidation is the loss of electrons (oxidation number increases); reduction is the gain of electrons (oxidation number decreases). Remember LEO the lion says GER, or OIL RIG.

12. What are the oxidizing agent and reducing agent in a redox reaction?

    The oxidizing agent is the species that is reduced (it gains electrons, causing oxidation of another); the reducing agent is the species that is oxidized (it loses electrons, causing reduction of another).

13. What is the difference between an electrolytic cell and a voltaic (galvanic) cell?

    A voltaic cell uses a spontaneous redox reaction to produce electrical energy (chemical→electrical). An electrolytic cell uses an external electrical source to drive a nonspontaneous reaction (electrical→chemical).

14. In any electrochemical cell, at which electrode does oxidation occur and at which does reduction occur?

    Oxidation always occurs at the anode; reduction always occurs at the cathode (mnemonic: AN OX, RED CAT).

15. What is an organic compound, and what element is always present?

    An organic compound is a compound that always contains carbon (typically bonded to hydrogen); carbon's ability to form four covalent bonds allows it to make chains, rings, and many compounds.

16. What is the difference between a saturated and an unsaturated hydrocarbon?

    A saturated hydrocarbon contains only single carbon-carbon bonds (alkanes); an unsaturated hydrocarbon contains at least one double (alkene) or triple (alkyne) carbon-carbon bond.

17. What is the general formula for alkanes, alkenes, and alkynes?

    Alkanes: CnH2n+2 (single bonds); alkenes: CnH2n (one double bond); alkynes: CnH2n−2 (one triple bond).

18. What are isomers?

    Compounds that have the same molecular formula but different structural arrangements of atoms, giving them different properties (e.g., butane and 2-methylpropane, both C4H10).

19. Identify the functional group families: -OH and -COOH.

    -OH is the hydroxyl group of an alcohol; -COOH is the carboxyl group of an organic (carboxylic) acid.

20. What is the difference between a chemical reaction and a nuclear reaction?

    Chemical reactions involve the valence electrons and rearrange atoms without changing the nucleus; nuclear reactions involve changes in the nucleus (protons/neutrons), can change one element into another, and involve far greater energy.

21. Compare alpha, beta, and gamma radiation in terms of charge, mass, and penetrating power.

    Alpha (He nucleus, +2 charge, heavy, least penetrating, stopped by paper); beta (electron, -1 charge, light, moderate penetration, stopped by aluminum); gamma (high-energy photon, no charge, no mass, most penetrating, needs lead/concrete).

22. What is half-life?

    The time required for half of the atoms (nuclei) in a radioactive sample to decay; it is constant for a given isotope regardless of sample size.

23. If a 100 g sample of a radioactive isotope has a half-life of 10 years, how much remains after 30 years?

    30 years = 3 half-lives. 100 g → 50 g → 25 g → 12.5 g, so 12.5 g remains.

24. What is the difference between nuclear fission and nuclear fusion?

    Fission is the splitting of a large nucleus into smaller nuclei (releasing energy, used in nuclear reactors); fusion is the combining of small nuclei into a larger one (releasing even more energy, as in the sun).

What this deck covers

Physical Setting / Chemistry (Regents Examination) flashcards FAQ