AP Chem Semester 1 Exam – Flashcards
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| In what type of radioactive decay does the atomic number of the product increase by one? a) alpha, b) gamma, c) electron capture, d) positron emission, e) beta |
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| Neutron into proton, so a) Alpha |
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Silver has two naturally occuring isotopes with the following isotopic masses: The average atomic mass of silver is 107.8682amu. The fractional abundance of the lighter of the two isotopes is _. |
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106.90509(X) 108.9047(1-X) 108.9-108.9(x)+106.9(x) = 107.87
c) .51835 |
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In the symbol below, x=_. a) 13, |
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| e) not enough information to determine |
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The element _ is most similar to Sr in chemical and physical properties.
a) At, b) Rb, c) Cs, d) Li, e) Ba |
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| e) Ba , In the same group. |
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The atomic mass unit is presently based on assigning an exact integral mass (in amu) to an isotope of _.
a) He, b) H, c) O, d) Na, e) C |
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| e) C |
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The law of constant composition applies to _. A)homo. Mixtures B)Compounds C)Hetero. Mixtures D)Solutions E)Solids |
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| B) compounds |
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| Which one of the following is NOT an intensive property? A)Temperature B)Boiling point C)Melting point D)Mass E)Density |
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| D)Mass |
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| If matter is uniform throughout and cannot be separated into other substances by physical processes, but can be decomposed into other substances by chemical processes, it is a _. A)Hetero mix. B)Mix of elements C)Compound D)Homo. Mix E)Element |
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| C)Compound |
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| The correct name for CaH2 is _. A)Calcium Hydride B)Calcuim hydroxide C)Calcium dihydroxide D)Calcium Dihydride E)Hydrocalcium |
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| A)Calcium Hydride |
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| The proper formul for the hydronium ion is _. A)H- B)OH- C)H3O+ D)NH4+ E)N-3 |
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| C)H3O+ |
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| A certain mass of carbon reacts with 13.6g of oxygen to form carbon monoxide. _g of oxygen would react with the same mass of carbon to form carbon dioxide, according to he law of multiple properties? A)27.2 B)6.8 C)25.6 D)13.6 E)136 |
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| Doubled, not halved. A)27.2 |
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| The charge on an electron was determined in the _. A)atomic theory of matter B)cathode ray tube, by J.J. Thompson C)Millikan oil drop experiment D)Dalton atomic theory E)Rutherford gold foil experiment |
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| C)Millikan oil drop experiment |
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| Element M reacts with fluorine to form an ionic compound with the formula MF3. The M-ion has 18 electrons. Element M is _. A)Ar B)Sc C)Cr D)Ca E)P |
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| M is a metal. B)SC |
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| The formula of a salt is XCl2. The X-ion in this salt has 28 electrons. The metal X is _. A)Pd B)Ni C)Fe D)V E)Zn |
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| Don't guess. A)Zn |
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| Which of the following of Dalton's postulates are no longer valid? 1: Each element is composed of extremely small particals called atoms 2: Atoms are indivisible 3: Atoms of a given element are identical 4:Atoms of different elements are different and have different properties. A)1&2 B)2&3 C)only2 D)3&5 E)only3 |
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| B)2&3 |
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| The correct name for H2 SO3 is _. A)Sulfer Hydroxide B)Sulfuric acid C)sulfurous acid D)Hydrosulfuric acid E)Hydrosulfic acid |
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| C)sulfurous acid |
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| 1 picometer= _ centimeters A)1x10^10 B)1x10^-12 C)1x10^8 D)1x10^-8 E)1x10^-10 |
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| E)1x10^-10 (Not from base) |
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| Which atoom has the largest number of neutrons? A)Cl-37 B)K-39 C)Ar-40 D)Ca-40 E)P-30 |
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| C)Ar-40 |
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| Which one of the following is true about the liter? A)It is equivalent to a cubic decimeter B)It is slightly smaller than a gallon C)It is slightly smaller than a quart D)It is the SI base unit for volume E)It contains 10^6 cubic cm |
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| A)It is equivalent to a cubic decimeter. |
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| The correct formula for Mo(IV) hypochlorite is _. A)Mo(ClO4)4 B)Mo(ClO2)4 C)Mo(ClO)4 D)MoCl4 E)Mo(ClO3)4 |
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| C)Mo(ClO)4 |
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| How many atoms of He are there in a balloon that contains 40.0g of He? A)3.01E23 B)6.02E23 C)12.04E23 D)6.02E24 E)12.04E24 |
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| D)6.02E24 |
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| What is the lowest whole number coefficient for the water molecule when octane, C8H18, is burned in air? A)2 B)9 C)12 D)16 E)18 |
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| E)18 |
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| BaCl2 is a hydrated salt. A 1.25g sample of the hydrate is heated in an oven until it does not lose additional mass. The anhydrous BaCl2 has a mass of 1.06g. What is the formula of the hydrate? A)BaCl2:H2O B)BaCl2:2H2O C)BaCl2:3H2O D)BaCl2:5H2O E)BaCl2:12H20 |
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| B)BaCl2:2H2O |
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| W metal can be prepared by reacting WO3 with H2 gas which produces metallic W and Water. How many grams of W may be prepared from .0500mol of WO3 and excess H? A)5.58g B).5g C)9.19g D)184g E)18.4g |
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| A)5.58g |
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| Which of these is an oxi-redox reaction? A)HC2H2O(Aq) + NH3(aq) > C2H3O2(aq) + NH4 B)Ba+2(aq) + SO4-1(aq) > BaSO4(s) C)NaOH(aq) + HF(aq) > H2O(aq) + NaF(aq) D)2K(s) + Br2(L) > 2KBr(s) E)NaHCO3(s) + HCl(aq) > NaCl(aq) + H2O(l) + CO2(g) |
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| D)2K(s) + Br2(l) > 2KBr(s) |
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| The total concentration of H+ ions in a 0.250 M solution of H2SO4 is _____: A)essentially zero B)0.125 M C)0.250 M D)0.500 M E)0.750 M |
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| D)0.500 M |
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| In a double replacement reaction, formation of which of the following does not necessarily lead to a chemical change? A)HC2H2O2 B)H2S C)AgCl D)NaCl E)CO2 |
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| D)NaCl |
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| How many grams of H3PO4 are in 175mL of a 3.5 M solution of H3PO4? A)0.61 B)60 C)20 D)4.9 e)612 |
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| B)60 |
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| All of the following are oxidation-reduction reactions, EXCEPT: a)Calcium oxide and water form calcium hydroxide b)H gas reacts with Br gas to form hydrogen bromide c)Calcium metal reacts with hydrochloric acid to form CaCl and H gas d)NaBr and F gas react to form NaF and Br gas e)Water decomposes to H gas and O gas |
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| a)CaO and water form CaOH |
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| The net ionic equation for the reaction between aqueous solutions of HF and KOH is a)HF + KOH > H2O + K+ + F- b)HF + OH > H2O + F- c)HF + K+ + OH- > H2O + KF d)H+ + OH- > H2O e)H+ + F- + K+ + OH- > H2O + K+ + F- |
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| Either b)HF + OH- > H2O + F- or d) H+ + OH- > H2O |
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| Which of the following is a strong acid? a) H2CO3 b)HF c)H3PO4 d)HClO3 e)HNO3 |
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| b)HF |
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| When a system, _, /_E is always negative, a)absorbs heat and does work b)gives off heat and does work c)absorbs heat and has work done on it d)gives off heat and has work done on it e)none of the above is always negative |
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| b) gives off heat and does work |
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| Which one of the following is an endothermic process? a)ice melting b)water freezing c)Boiling soup d)HCl and BaOH are mixed at 25C and the temperature increases. e)Both A and C |
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| E)Both a and c |
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| Of the following, which one is a state function? a) /_H b)q c)w d)heat e)None of the above |
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| a) /_H |
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| CH4(g) + 2O2(g) > CO2(g) + 2H2O(l) /_H= -889.1 kJ /_Hf : H2O(l)= -285.8 kJ/mol /_Hf : CO2(g)= -393.3 kJ/mol What is the standard heat of formation of methane, /_Hf CH4(g), as calculated from the data above? a)-210 kJ/mol b)-107.5 kJ/mol c)-75.8 kJ/mol d)75.8 kJ/mol e)210 kJ/mol |
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| c) -75.8 kJ/mol [(2x-285.8)+-393.3]-x= -889.1 |
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| What is the standard enthalpy change, /_H, for the reaction represented below? C6H6(g) > C2H2(g) (/_Hf of C2H2(g) is 230 kJ/mol; /_Hf of C6H6(g) is 83 kJ/mol.) a)-607kJ b)-147kJ c)-19kJ d)+19kJ e)+773kJ |
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| a)-607kJ |
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| Under what condition(s) is the enthalpy change of a process equal to the amount of heat transferred into or out of the system? a. Temp is constant b. Pressure is constant c. Volume is constant a) a only b) b only c) c only d) a and b e) b and c |
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| b) b only |
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| The units of heat capacity are _. a)K/J or C/J b)J/K or J/C c)J/g-K or J/g-C d)J/mol e)g-K/J or g-C/K |
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| b)J/K or J/C |
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| Of the following, /_Hf is NOT zero for _. A)O2(g) B)C(graphite) C)N2(g) D)F2(s) E)Cl2(g) |
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| d)F2(s) Gas in natural state |
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| Which of the following is a statement of Hess's law? A)If a reaction is carried out in a serious of steps, the /_H for the reaction will equal the sum of the enthalpy changes for the individual steps B)If a reaction is carried out in a serious of steps, the /_H for the reaction will equal the product of the enthalpy changes for the individual steps C)The /_H process in the forward direction is equal in magnitude and opposite in sign to the /_H for the process in the reverse direction D)The /_H for a process in the forward direction is eequal to the /_H for the process in the reverse direction E)The /_H of a reaction depends on the physical states of the reactants and products |
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| a)If a reaction is carried out in a series of steps, the /_H for the reaction will equal the sum of the enthalpy changes for the individual steps |
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| The units of specific heat are _. A)K/J or C/J B)J/K or J/C C)J/g-K or J/g-C D)J/mol E)g-K/J or g-C/J |
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| C)J/g-K or J/g-C |
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| With reference to enthalpy changes, the term standard conditions means _. A.P=1atm B.some common temperature, usually 298K C.V=1L A)a only B)b only C)c only D)a and c E)a and b |
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| E)a and b |
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| In the Bohr model of the atom, _. a)Electrons can have any energy b)Electron energies are quantized c)Electrons travel in circular paths called orbitals d)Electron paths are controlled by probability e)both a and c |
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| B)Electron energies are quantized (Ex. pebbles and water) |
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| Which quantum numbers must be the same for the orbital tht they designate to be degenerate in a many-electron system? A)n only B)n and l only C)Ms only D)n, l, Ml, and Ms E)n, l, and Ml |
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| B)n and l only |
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| Wich one of the following represents an impossible set of quantum numbers for an electron in an atom? (Arranged as n,l,Ml,Ms) A)1,0,0,1/2 B)5,4,-3,-1/2 C)5,4,-3,1/2 D)3,3,3,1/2 E)2,1,-1,-1/2 |
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| D)3,3,3,1/2 |
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| An electron in a Bohr hydrogen atom has an energy of -1.362 x 10^-19J. The value of n for this electron is _. A)1 b)2 c)3 d)4 e)5 |
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| D)4 |
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| Which one of the following conigurations depicts an excited oxygen atom? A)1s2 2s2 2p2 3s2 B)1s2 2s2 2p1 C)[He]2s2 2p4 D)1s2 2s2 2p4 E)1s2 2s2 2p2 |
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| A)1s2 2s2 2p2 3s2 |
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| The de Broglie wavelength of a _ will have the shortest wavelength when traveling at 30cm/s. A)U atom B)H atom C)Car D)Planet E)Marble |
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| D)Planet Mass up, wavelength down (trend) |
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| Electromagnetic radiation with a wavelength of 525nm appears as green light to the human eye. The energy of one photon of this light is _J. A)3.79x10^-28 B)2.64x10^18 C)1.04x10^-22 D)3.79x10^-19 E)1.04x10^-31 |
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| D)3.79x10^-19 |
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| A radio station broadcasts at 103.5MHz. The wavelength of the signal is _m. A)2.75 b)3.84 c)2.90 d)4.71 e)3.10 |
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| C)2.90m |
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| Which equation correctly represents the first ionization of phosphorus? a)P-(g) > P(g) + e- b)P(g) + e- > P-(g) c)P(g) > P-(g) + e- d)P(g) > P+(g) + e- e)P+(g) + e- > P(g) |
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| D)P(g) > P+(g) + e- |
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| Which equation correctly represents the electron affinity of Ca? A)Ca-(g) > Ca(g) + e- B)Ca(g) > Ca+(g) + e- C)Ca(g) + e- > Ca-(g) D)Ca(g) > Ca-(g) + e- E)Ca+(g) + e- >Ca(g) |
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| C)Ca(g) + e- > Ca-(g) |
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| Using the Born-Haber cycle, the /_Hf of KBr is equal to . A)/_Hf [K(g)]+/_Hf[Br(g)]-I1-E(Br)+/_H-lattice B)/_Hf[K(g)]+/_Hf[Br(g)]+I1(K)+E(Br)+/_H-lattice C)/_Hf[K(g)]-/_Hf[Br(g)]+I1(K)-E(Br)+/_H-lattice D)/_Hf[K(g)]+/_Hf[Br(g)]+I1(K)+E(Br)-/_H-lattice E)/_Hf[K(g)]-/_Hf[Br(g)]-I1(K)-E(Br)-/_H-lattice |
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| A)/_Hf[K(g)]+/_Hf[Br(g)]-I1-E(Br)+/_H-lattice |
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| Which of the following has the bonds correctly arranged in order of increasing polarity? A)Mg-F,Be-F,N-F,O-F B)Be-F,Mg-F,N-F,O-F C)O-F,N-F,Be-F,Mg-F D)N-F,Be-F,Mg-F,O-F E)O-F,Be-F,Mg-F,N-F |
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| C)O-F,N-F,Be-F,Mg-F |
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| In the Lewis symbol for a sulfur atom, there are _ paired and _ unpaired electrons. A)4,2 B)2,4 C)2,2 D)5,1 E)0,6 |
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| A)4,2 |
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| The oxidation number of phosphorus in PF3 is _. A)+3 B)+2 C)+1 D)-3 E)-2 |
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| A)+3 |
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| A valid lewis structure of _ cannot be drawn without violating the octet rule. A)BeH2 B)NF3 C)SO2 D)SO3^-2 E)CF4 |
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| A)BeH2 |
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| Bond enthalpy is _. A)Sometimes positive, sometimes negative B)always positive C)Always negative D)Always zero E)Unpredictable |
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| B)Always positive |
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| The formal charg on nitrogen in NO3- is _. A)0 B)+1 C)-2 D)+2 E)-1 |
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| B)+1 |
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| The basis of the VSEPR model of molecular bonding is _. A)Atomic orbitals of the bonding atoms must overlap for a bond to form B)Regions of electron density in the valence shell of an atom will arrange themselves so as to maximize overlap C)Hybrid orbitals will form as necessary to, closely as possible, achieve spherical symmetry D)Electron domains in the valence shell of an atom will arrange themselves so as to minimize repulsions E)Regions of electron density on an atom will organize themselves so as to maximize s-character |
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| D)Electron domains in the valence shell of an atom will arrange emselves so as to minimize repulsions |
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| The electron-domain geometry of _ is trahedral A)CBr4 B)CCl2Br2 C)PH3 D)XeF4 E)all of the above except XeF4 |
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| E)all of the above except XeF4 |
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| Of the molecules below, only _ is nonpolar A)CO2 B)H2O C)NH3 D)TeCl2 E)HCl |
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| B)H2O |
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| Three monosulfur fluorides are observed: SF2, SF4, and SF6. Of these, _ is/are nonpolar. A)SF2 and SF4 only B)SF4 only C)SF6 only D)SF2,SF4, and SF6 E)SF2 only |
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| A)SF2 and SF4 only |
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| The electron-domain geometry of a carbon-centered compound is tetrahedral. The hybridization of the central carbon atom is _. A)sp3d B)sp3d2 C)sp2 D)sp3 E)sp |
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| D)sp3 |
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| The sp2 atomic hybrid orbital set accommodates _ electron domains. A)2 B)3 C)4 D)5 E)6 |
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| B)3 |
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| The hybridization scheme for BeF2 is _. A)sp3d2 B)sp2 C)sp3d D)sp3 E)sp |
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| D)sp3 |
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| The hybridization of the central atom in the XeF4 molecule is _. A)sp3d2 B)sp2 C)sp D)sp3 E)sp3d |
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| A)sp3d2 |
