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MCAT Chemistry

Subjects : mcat, science
Instructions:
  • Answer 50 questions in 15 minutes.
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  • Match each statement with the correct term.
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This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Structure that occurs when it is possible to draw two or more valid electron dot structures that have the same number of electron pairs for a molecule or ion






2. Simplest whole # ration of atoms in a compound






3. The amount of energy that reactants must absorb before a chemical reaction will start; also called free energy of activation.






4. A reaction in which atoms of one element take the place of atoms of another element in a compound






5. Common definition of acids as proton (H+) donors and bases as proton acceptors






6. Contains nonmetals that are non - reactive. Full outermost energy level except helium which has 2.






7. An equilibrium expression used to measure weak - acid strength - given by the ratio of the product of the products' molar concentrations to the product of the reactants' molar concentrations - with each term raised to the power of its stoichiometric






8. Process by which molecules tend to move from an area where they are more concentrated to an area where they are less concentrated






9. A measured amount of a solution of unknown concentration is added to a known volume of a second solution until the reaction between them is just complete






10. A substance that - when dissolved in water - results in a solution that can conduct electricity






11. Region in a molecule where atomic orbitals overlap - resulting in either a stable low - energy bonding orbital or an unstable high - energy antibonding orbital.






12. A chemical reaction involving the transfer of one or more electrons from one reactant to another; also called oxidation - reduction reaction.






13. Halogens; ns2np5 - - 2nd most reactive group - The Halogens; very active because of need to fill; form -1 ions; 7 electrons in valence shell; tend to form salts with elements from groups 1A and 2A






14. Side - to side parallel orbitals overlap to share electrons - the 2nd/3rd covalent bond between two atoms - cannot rotate and maintain the bond.






15. The molar solubility of one salt is reduced when another salt - having a common ion is brought into the same solution






16. Alkali metals: highly reactive - therefore always compounds. - 1 valence electron +1 ion - Hydrogen H? - Lithium Li? - Sodium Na? - Potassium K? - Rubidium Rb? - Cesium Cs?






17. Defined acids as subtsances that produced H ions in water - while bases produced OH ions. When they reacted together - H and OH neutralise to make water






18. 2.18 x 10^-18 J/electron






19. The average distance between the nuclei of two bonded atoms






20. An atom or group of atoms that has a positive or negative charge






21. Where half of the acid is neutralized by the base on a titration curveAn acid dissociation constant - Ka - (also known as acidity constant - or acid - ionization constant) is a quantitative measure of the strength of an acid in solution. It is the eq






22. Spectrum of certain absorbed wavelengths of light corresponding to an atom's spectrum of emitted frequencies of light. Unique to each element. AAS can be used to indentify an element.






23. When a solute is dissolved in a solvent - it will dissociate until reaching an equilibrium point at which the rate of dissociation equals the rate of precipitation of the solute - regardless of any additional solute introduced into the mixture






24. An element in an 'A' group in the periodic table; as a group these elements display a wide range of physical and chemical properties. In their atoms - the s and p sublevels in the highest occupied energy level are partially filled






25. 1913 - Niels Bohr - said that electrons formed specific layers instead or random ones - said atoms atoms absorb and give off energy when the electrons move from one shell to another






26. Solids in which the particles are arranged in a repeating - 3- D pattern - has a specific melting point - classified as ionic network covalent - metallic or molecular.






27. A set of spectral lines that appear in the visible light region when a hydrogen atom undergoes a transition from energy levels n>2 to n=2.






28. Second quantum number - designated by the letter 'l.' This 'angular momentum' refers to the subshells within each principle quantum energy level. It can take on the value of an integer in the 0 to (n -1) range. The four subshellscorresponding to l=0






29. A pair of equal and opposite electric charges or magnetic poles separated by a small distance






30. The area of chemistry that is concerned with reaction rates and reaction mechanisms






31. (chemistry) any theory in which all matter is composed of tiny discrete finite indivisible indestructible particles






32. Keq describes the ratio of product concentration to reactant concentration - with each raised to the power corresponding ot its coefficient ion in the balanced equation






33. The point on a phase diagram that represents the only set of conditions at which all three phases exist in equilibrium with one another






34. (chemistry) a substance formed by chemical union of two or more elements or ingredients in definite proportion by weight






35. (chemistry) the sum of the relative atomic masses of the constituent atoms of a molecule






36. Sol - a chemical process in which solvent molecules and molecules or ions of the solute combine to form a compound






37. Any sample of a given compound will contain the same elements in the identical mass ratio.






38. The quantum number that has only two possible values - +1/2 and -1/2 - which indicate the two fundamental spin states of an electron in an orbital






39. (chemistry) separation of a substance into two or more substances that may differ from each other and from the original substance






40. The weight in grams of compound that can be substituted by 1 atom of Hydrogen. GEW = MW / # of acidic Hyrdogens






41. (chemistry) a series from actinium to lawrencium of 15 radioactive elements with increasing atomic numbers






42. A set of frequencies of electromagnetic waves given off by atoms of an element; consists of a series of fine lines of individual colors






43. An atom - ion - or molecule that donates an electron pair to form a covalent bond.






44. States that if a stress is applied to a system at equilibrium - the system shifts in the direction that relieves the stress.






45. An elementary particle with 0 charge and mass about equal to a proton






46. The weight in grams of one mole of a given elementand is expressedin tems of grams per mole.






47. Valence Shell Electron Pair Repulsion theory - stating that the three - dimensional molecular geometry about some central atom is determined by the elctronic repulsion between its bonding and nonbonding electron pairs.






48. Systematic pairing of a deprotonated species (base) with its protonated form (conjugate acid). Conjugates appear on opposite sides of a chemical equation.






49. The tendency for an atom to attract electrons to itself when it is chemically combined with another element






50. A horizontal row of elements in the periodic table