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Mc020-2.jpgH = 98.8 kJ, and mc020-3.jpgS = 141.5 J/K. Is this reaction spontaneous or nonspontaneous at high and low temperatures?
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Which statement best describes how dynamic equilibrium relates to a saturated solution of sodium chloride?
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In the hypothetical reaction below, substance A is consumed at a rate of 2.0 mol/L·s. If this reaction is at dynamic equilibrium, at what rate will substance B be consumed?
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Victor pours 100 grams of oil into a beaker filled with 1,000 grams of water. What is the total mass of his mixture? A. 100,000 grams B. 1,100 grams C. 900 grams D. 10 grams
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Victor pours 100 grams of oil into a beaker filled with 1,000 grams of water. What is the total mass of his mixture? A. 100,000 grams B. 1,100 grams C. 900 grams D. 10 grams
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Select all of the items that are true about a sample of water vapor at 101°C as it cools. A) Its temperature will fall continuously until it condensed into a liquid. B) Its temperature will fall stea
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Holly reacts 625.0 mL of 0.4899 M AgNO3 with excess Na3PO4 to form a precipitate of Ag3PO4. Calculate theoretical yield in grams
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Consider the molecule h2co. using valence bond theory, describe the location of the carbon electrons as it prepares to form bonds with the other atoms.
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A radioactive isotope of copper decays as follows: 64cu → 64zn + 0 β −1 t1/2 = 12.8 h starting with 92.0 g of 64cu, calculate the quantity of 64zn produced after 14.3 h.
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An atom is ionized so that it has only one electron. when the electron drops from the n = 3 shell to the n = 1 shell, an x-ray of wavelength 140.70 pm is emitted. what is the atomic number?
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Ammonia can be prepared by the reaction of magnesium nitride with water. the products are ammonia and magnesium hydroxide. when the equation is written and balanced, the coefficient of magnesium nitri
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A 250 milliliter sample of hydrogen was collected over water at 20◦c on a day when the atmospheric pressure was 756 torr. the vapor pressure of water under these conditions is 17.54 torr. what volum
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A freshly isolated sample of 90y was found to have an activity of 5.0 × 105 disintegrations per minute at 1:00 p.m. on december 3, 2006. at 2:15 p.m. on december 17, 2006, its activity was measured a
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Anna stated that ionic compounds have high melting points and low boiling points. She said that this demonstrates that ionic compounds have strong bonds because a lot of energy is needed to break the
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If the reaction of 5.75 moles of sodium with excess hydrofluoric acid produced an 86.5% yield of hydrogen gas, what was the actual yield of hydrogen gas? Unbalanced equation: Na + HF yields NaF + H2
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What happens when molten material travels along the underside of the crust? A. It rises up towards the crust. B. It cools and sinks towards the core. C. Lava travels away from the core and forms the c
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Which of the following could be a method used to estimate the age of an ancient rock? A. To find out its mineral composition B. To find the age of the fossils trapped in it C. To calculate the amou
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How is Earth’s surface likely to change along the edges of a bend in a river channel? A. Erosion takes place along the inner edge as water flows relatively slowly. B. Erosion takes place along the
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Which of these is an example of a physical change? A-a banana ripening in the air B-hydrogen burning in the air C-zinc reacting with an acid D-liquid water turning into vapor
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Give a sequence of reagents (inorganic or monofunctional organic with 4 or fewer carbons), in order, one per line, that will produce ch3ch2ch2c(ch3)(ch2ch3)ch=o
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What causes the appearance of lines in an emission spectrum? Light is absorbed as an electron moves to a higher energy state. Light is released as an electron moves to a lower energy state. An electro
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The electrons in the bond between hydrogen and fluorine are more strongly attracted to the bottom atom of
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Identify the combination reaction. A. C4H12+7O2 -->6H2O+4CO2 B. 2H2+O2-->2H2O C. AI2S3-->2AI+3S D. CI2+2KBr-->2KCI+Br2
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Which molecule has polar bonds that do not cancel each other out? A. Water B. Carbon Dioxide C. Fluorine gas (a diatomic molecule, F2) D. Bromine liquid (a diatomic molecule, Br2)
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Compound a has the formula c9h19cl. b is a c9h19br compound. a and b undergo base-promoted e2 elimination to give the same alkene c as the major product as well as different minor products. c reacts w
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Calculate the ph of a 0.50 m solution of sodium acetate (nach3coo) given that the ka of acetic acid (ch3cooh) is 1.8 x 10-5.
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The reaction of n−bromosuccinimide with 4−methyl−3−nitroanisole has been reported in the chemical literature. this reaction yields a single product in 95% yield. identify the product formed fr
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The diagram below is an artist’s impression of a single atom of element Be. The neutrons are shown with stripes, the protons are gray, and the electrons are black. These particles are not drawn to s
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The central vacuole in a plant cell is responsible for turgor pressure. When the vacuole loses water the cytoplasm "shrinks". When the vacuole gains water the cytoplasm seems to "puff up". One structu
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Incineration and landfills are the most widely-used waste management methods. Incineration is the burning of garbage and is favored by small countries that lack adequate landfill space. This method ca
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Consider the following reaction. H2O + F– <---> HF + OH– What is the conjugate base of H2O? a) H2O b) F– c) OH–
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How are carbon dioxide (co2) levels in the atmosphere affected by tectonic uplift of rocks and their resultant chemical weathering?
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When acids and bases in solution balance each other out, the solution is said to be: A. A compound B. A neutral solution C. A Basic solution
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Which statement about supercell storms is false? A. A supercell storm occurs only during the winter months. B. A supercell storm is characterized by rotating updrafts. C. A supercell storm can develop
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2 NaClO3 --> 2 NaCl + 3 O2 In order to produce 6 moles of oxygen gas, how many moles of sodium chlorate are required?
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Which of the following is a balanced equation for this reaction? A. H2SO4 + Pb(OH)4?Pb(SO4)2 + H2O B. 2H2SO4 + Pb(OH)4?Pb(SO4)2 + 4H2O C. 2H2SO4 + Pb(OH)4?Pb(SO4)2 + 2H2O D. 2H2SO4 + Pb(OH)4?Pb(SO4)2
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Odium and Chlorine combine to form table salt. Given the chemical reaction, how many grams of 2Na + Cl2 would be required to produce 4 grams of table salt?
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Write the reaction responsible for the formation of bubbles. alka-seltzer, a drugstore antacid, contains a mixture of nahco3, aspirin, and citric acid, c6h5o7h3.
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If the vapor pressure of ethylene glycol is 7.23 mm hg at 95.1°c and 755 mm hg at 197.1°c, what is the heat of vaporization of ethylene glycol?
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How many grams of helium must be released to reduce the pressure to 73 atm assuming ideal gas behavior?
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Calculate the amount of heat needed to melt 104.g of ice ( h2o ) and bring it to a temperature of 12.2°c . be sure your answer has a unit symbol and the correct number of significant digits.
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Ammonia reacts with diatomic oxygen to form nitric oxide and water vapor: 4nh3 + 5o2 ï® 4no + 6h2o what is the theoretical yield of water, in moles, when 40.0 g nh3 and 50.0 g o2 are mixed and allow
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In a double-displacement reaction, sodium sulfide, Na2S, reacts with silver nitrate, AgNO3, to form sodium nitrate, NaNO3, and silver sulfide, Ag2S. Balance this equation.
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Which is the best term to use when describing the energy of position? chemical kinetic potential electromagnetic
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Which statement correctly describes the actual yield and the theoretical yield of a reaction? The actual yield is calculated from the reactant amounts, but the theoretical yield must be measured for e
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The mass of the sun is 1.989 x 10^30 kg, and the mass of the earth is 5.974 x 10^24 kg. How many Earths would be needed to equal the mass of the sun?
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The Dalton model of the atom predicted which of the following? A. Electrons are embedded in a sphere. B. Atoms can be broken down into smaller components. C. Atoms have a nucleus. D. All matter is
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When are elements most likely to become unreactive? when they share all of their valence electrons when their valence shell is completely full when they have lost all of their valence electrons wh
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Describe the composition of the nucleus of an atom. A) It is composed of protons. B) It is composed of protons and neutrons. C) It is composed of protons and electrons. D) It is composed of protons, n
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Match the term with its description. Match Term Definition Colloid A) A mixture in which two or more liquids are mixed that normally are not mixable Emulsion B) Mixture that has its different componen
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