Chemistry Test 3 Test Answers – Flashcards
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A hot piece of iron is dropped into a beaker containing colder water. Which of the following statements is/are CORRECT? 1. Energy is transferred as heat from the iron to the water. 2. Thermal equilibrium is attained when the iron and the water reach the same temperature. 3. Thermal energy from the iron is converted to electrostatic energy in the water.
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1 and 2 Energy is transferred as heat from the iron to the water Thermal equilibrium is attained when the iron and the water reach the same temperature
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Specific heat capacity is?
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The quantity of heat needed to change the temperature of 1.00 g of a substance by 1K
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If 495 J is required to change the temperature of 12.7 g of sodium chloride from 275.0 K to 335.0 K, what is the specific heat capacity of sodium chloride?
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0.650 J/g*K
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The same amount of energy in the form of heat is added to 5.00 g samples of each of the metals below, which metal will undergo the largest temperature change? Metal Specific Heat Capacity (J/g*K) Ag 0.235 Al 0.897 Cu 0.385 Fe 0.449 Hg 0.140
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Hg
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How much energy (in kJ) is required to change the temperature of 32 degrees celsius to 815 degrees celsius. The specific heat capacity of aluminum is 0.897 J/g*K.
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228 kJ
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The heat of vaporization of benzene C6H6 is 30.7 kJ.mol at its boiling point of 80.1 degrees celsius. How much energy in the form of heat is required to vaporize 102 g benzene at its boiling point?
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40.1 k
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When 66.0 g of an unknown metal at 28.5 degrees celsius is placed in 83.0 g H2O at 78.5 degrees celsius, the water temperature decreases to 75.9 degrees celsius. What is the specific heat capacity of the metal? The specific heat capacity of water is 4.184 J/g*K
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0.29 J/g*K
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The thermochemical equation for the combustion of methanol is shown below. CH3OH(l) +3/2 O2(g) yields CO2(g) + 2H2O(g)
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-171 kJ
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The thermochemical equation for the combustion of butane is shown below. Ch4H10(g)+13/2 O2(g) yeilds 4 CO2(g) + 5 H2O(l) What is the enthalpy change for the following reaction? 8 CO2(g) +10 H2O(l) yields 2 C4H10(g) + 13 O2(g)
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+5754 kJ/mol-rxn
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Iron oxide reacts with aluminum in an exothermic reaction. Fe2O3(s) + 2 Al(s) yields 2 Fe(s)+ Al2O3(s) The reaction of 5.00 g Fe2O3 with excess Al (s) evolves 26.6 kJ of energy in the form of heat. Calculate the enthalpy change per mole of Fe2O3 reacted.
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-8.50 x 10^2 kJ/mol
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Determine delta H degree for the following reaction, 2 NH3(g) +5/2O2(g) yields 2 NO(g) + 3 H2O(g) given the thermochemical equations below. N2(g) + O2(g) yields 2 NO(g) N2(g) + 3 H2(g) yields 2 NH3(g) 2 H2(g) + O2(g) yields 2 H2O(g)
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-452.8 kJ/mol-rxn
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Which 1`combination of atoms is most likely to produce a compound with covalent bonds?``
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S and Cl
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Which combination of atoms is most likely to produce a compound with ionic bonds?1
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Mg and O
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An arsenic atom has _____ valence electrons.
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5
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Place the following ions in order from smallest to largest ionic radii: K+, Na+, Mg2+, and Al3+.
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Al3+<Mg2+<Na+<K+
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Which of the following elements has the most negative electron affinity?
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F
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Rank F, Cl, and Br in order of increasing first ionization energy.
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Br < Cl< F
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Place the following atoms in order of increasing atomic radii: Se, Sb, Br, and Te.
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Br < Se < Te < Sb
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What 2- ion has the following ground state electron configuration?
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sulfide ion
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Which one of the following atoms is paramagnetic in the ground electronic state?
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Bi
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Which element has the following ground state electron configuration?
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C
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Which element has the following ground state electron configuration for Cr3+
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[Ar] 3d3
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Which of the following is a d-block element?
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Hg
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Which of the following transitions would a hydrogen atom emit the lowest energy photon?
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n=3 to n=1
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All of the following quantum numbers are allowed except?
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n=2, l=2. ml=+1
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Which of the following statements is/are CORRECT?
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1 and 3 A paramagnetic substance is attracted to a magnetic field. Atoms with one or more unpaired electrons are paramagnetic.
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What type of orbital is designated n=3 l=2 and ml=-2
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3d
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What type of orbital is designated n=3 l=0 and ml=0
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3s
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What color of light has the lowest frequency?
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Red
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A green laser pointer emits light at 532.0 nm. What is the frequency of this radiation?
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5.635 x 10^14 s^-1
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If a cordless phone operates at a frequency of 9.00 x 10^8 s^-1. What is the wavelength of this radiation?
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0.333 m
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Excited sodium atoms emit light in the infrared at 589 nm. What is the energy of a single photon with this wavelength?
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3.37 x 10^-28 J
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Calculate delta H for the combustion of ammonia. using standard molar enthalpies of formation. molecule change in heat (kJ/mol-rxn)
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-1398.8 kJ/mol-rxn
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Which of the following atoms is paramagnetic in the ground electronic state?
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Bi
