chemistry
Question 1 (Multiple Choice Worth 2 points)[08.04]Which of the following best summarizes the main causes of water pollution today?[removed] increased runoff, driving, discarded oil[removed] evaporation, new construction, overpopulation[removed] waste from wildlife, decaying vegetation, automobiles[removed] leaking septic and sewer systems, manufacturing, farmingQuestion 2 (Multiple Choice Worth 2 points)[05.06]When 5.6 grams of NaCl are dissolved in enough water to create a 125-gram solution, what is the solution’s concentration, expressed as a percent by mass?[removed] 3.6% NaCl[removed] 3.8% NaCl[removed] 4.5% NaCl[removed] 4.7% NaClQuestion 3 (Multiple Choice Worth 2 points)[06.04]On a potential energy diagram for the following processes, which of the following has a decrease in entropy?[removed] melting[removed] freezing[removed] boiling[removed] sublimationQuestion 4 (Multiple Choice Worth 2 points)[07.02]Which of the following is the salt in the Brønsted-Lowry neutralization reaction?HBr + NaHCO3 H2CO3 + NaBr[removed] HBr[removed] NaHCO3[removed] H2CO3[removed] NaBrQuestion 5 (Multiple Choice Worth 2 points)[07.05]Which of the following is not a result when a change to an equilibrium system is applied?[removed] Increasing the rate of the forward reaction will cause a shift to the left.[removed] Increasing the rate of the reverse reaction will cause a shift to the left.[removed] Decreasing the rate of the forward reaction will cause a shift to the left.[removed] Decreasing the rate of the reverse reaction will cause a shift to the right.Question 6 (Multiple Choice Worth 2 points)[08.06]Biotechnology has allowed us to genetically modify corn with a gene that acts as a pesticide. What could be a possible environmental impact of this development?[removed] Insects resistant to the specific pesticide would develop over time.[removed] The surplus of corn would rot and decay releasing additional greenhouse gases.[removed] The price of corn would drop dramatically because of a greater supply with no increase in demand.[removed] Countries able to buy the new corn seeds would see increases in their economy and pollution would rise.Question 7 (Multiple Choice Worth 2 points)[07.05]What would happen if CH4 was removed from the following reaction that has reached equilibrium?CO (g) + 3H2 (g) CH4 (g) + H2O (g)[removed] The reaction would not be affected.[removed] The equilibrium would shift to the right.[removed] The equilibrium would shift to the left.[removed] The product concentration would equal the reactants.Question 8 (Multiple Choice Worth 2 points)[08.01]If the half-life of Technitium-104 is 18.0min, how much of a 14.2g sample will remain after 72 minutes?[removed] 3.55g[removed] 1.78g[removed] 0.888g[removed] 0.444gQuestion 9 (Multiple Choice Worth 2 points)[05.07]How many milliliters of a 1.25 molar hydrochloric acid (HCl) solution would be needed to react completely with 60.0 grams of calcium metal?Ca (s) + 2HCl (aq) CaCl2 (aq) + H2 (g)[removed] 1200 ml[removed] 2400 ml[removed] 3750 ml[removed] 9600 mlQuestion 10 (Multiple Choice Worth 2 points)[08.01]Which of the following statements is not true of gamma radiation?[removed] Gamma rays have no mass.[removed] Gamma rays severely damage living cells.[removed] Gamma rays are high frequency electromagnetic waves.[removed] Gamma rays are deflected toward the positive terminal in a magnetic field.Question 11 (Multiple Choice Worth 2 points)[06.02]On a potential energy diagram, what is true about activation energy?[removed] Activation energy is the same for both endothermic and exothermic reactions.[removed] Activation energy is greater for endothermic reactions.[removed] Activation energy is greater for exothermic reactions.[removed] Activation energy is represented by a negative slope.Question 12 (Multiple Choice Worth 2 points)[06.05]According to the collision theory and model created to explain the collision theory, why does a catalyst cause a reaction to speed up?[removed] It lowers the activation energy.[removed] It increases the collisions per minute.[removed] It increases the average kinetic energy of the particles.[removed] It increases the kinetic energy and the collisions per minute.Question 13 (Multiple Choice Worth 2 points)[07.02]If it requires 37.5 mL of a 0. 245 M HBr solution to neutralize 18.0 mL Mg(OH)2, what is the concentration of the Mg(OH) 2 solution?2 HBr + Mg(OH) 2 Mg(Br) 2 + 2 H2O[removed] 0.0120 M[removed] 0.0255 M[removed] 0.118 M[removed] 0.510 MQuestion 14 (Multiple Choice Worth 2 points)[07.06]Which of the following chemical reactions is an oxidation-reduction reaction?[removed] NO + 2H2 NH3 + H2O[removed] NaNO3 + LiF LiNO3 + NaF[removed] CaSO4 + 2KBr K2SO4 + CaBr2[removed] AgNO3 + 2HCl AgCl + 2HNO3Question 15 (Multiple Choice Worth 2 points)[08.03]Heat from the Earths core and pressure on the remains of dead plants and animals create which of the following resources?[removed] biofuel and hydro-electric[removed] natural gas and coal[removed] nuclear power and geothermal[removed] geothermal power and biofuelQuestion 16 (Multiple Choice Worth 2 points)[06.04]On a potential energy diagram, the activation energy is greatest under which of the following conditions?[removed] The potential energy of the products is greater than the reactants and the change in enthalpy is positive.[removed] The potential energy of the products is less than the reactants and the change in enthalpy is positive.[removed] The potential energy of the products is greater than the reactants and the change in enthalpy is negative.[removed] The potential energy of the products is less than the reactants and the change in enthalpy is negative.Question 17 (Multiple Choice Worth 2 points)[06.01]How would a system in which both matter and energy are exchanged freely between the system and the surroundings be classified?[removed] an open system[removed] an isolated system[removed] a closed system[removed] an integrated systemQuestion 18 (Multiple Choice Worth 2 points)[07.06]What is the oxidation number of sulfur (S) in magnesium sulfate (MgSO4)?[removed] +2[removed] +3[removed] +6[removed] +7Question 19 (Multiple Choice Worth 2 points)[06.03]Which substance will require more energy to heat if all the samples have the same mass?[removed] Lead[removed] Magnesium[removed] Iron[removed] AluminumQuestion 20 (Multiple Choice Worth 2 points)[05.01]Which of the following describes what occurs as a liquid becomes a solid?[removed] A physical change occurs; the particles of the liquid vibrate faster and their kinetic energy increases.[removed] A physical change occurs; the particles of the liquid vibrate more slowly and their kinetic energy decreases.[removed] A chemical change occurs; the particles of the liquid vibrate faster and their kinetic energy increases.[removed] A chemical change occurs; the particles of the liquid vibrate more slowly and their kinetic energy decreases.Question 21 (Multiple Choice Worth 2 points)[06.03]A 5.45g combustible sample is burned in a calorimeter. The heat generated changes the temperature of 555g water from 20.5°C to 39.5°C. How much energy is released by the burning? The specific heat of water is 4.18 J/ (°C × g).[removed] 564 J[removed] 2500 J[removed] 44100 J[removed] 138000 JQuestion 22 (Multiple Choice Worth 2 points)[08.02]How can a sample of uranium-235 that has critical mass be induced to react?[removed] It must be spilt with a laser.[removed] It must be fused to a helium nucleus.[removed] It must be bombarded it with neutrons.[removed] It must be shot with light speed electrons.Question 23 (Multiple Choice Worth 2 points)[07.01]What happens when an acid reacts with an active metal?[removed] A neutralization reaction occurs.[removed] Hydronium ion concentration is increased.[removed] Oxygen gas is produced.[removed] Hydrogen gas is produced.Question 24 (Multiple Choice Worth 2 points)[06.05]According to the collision theory and model created to explain the collision theory, what is the best explanation for why a higher temperature makes a reaction go faster?[removed] There are more collisions per minute.[removed] It increases the distance between the particles.[removed] It increases the average kinetic energy of the particles.[removed] It increases the average kinetic energy and there are more collisions per minute.Question 25 (Multiple Choice Worth 2 points)[07.04]Which answer describes a chemical reaction in equilibrium?[removed] The reactants are all used up.[removed] All the product is formed.[removed] The forward and reverse reactions have ceased.[removed] The forward and reverse reaction rates are the same.Question 26 (Multiple Choice Worth 2 points)[08.03]Which of the following best describes the forces that generate geothermal power?[removed] Heat energy beneath the Earth’s surface heats underground water into steam.[removed] Heat from the Earths core and pressure transform the remains of dead plants and animals.[removed] Energy of the sun strikes photovoltaic cells producing a flow of electrons.[removed] Heat energy is released during nuclear fission and steam is produced to turn a turbine.Question 27 (Multiple Choice Worth 2 points)[06.04]Which of the following circumstances will result in a reaction that is spontaneous at all temperatures?[removed] positive enthalpy change and positive entropy change[removed] negative enthalpy change and negative entropy change[removed] positive enthalpy change and negative entropy change[removed] negative enthalpy change and positive entropy changeQuestion 28 (Multiple Choice Worth 2 points)[05.06]Water is a polar molecule and attracts other polar molecules. Which of the following is a consequence of this property?[removed] Water is considered to be a universal solvent.[removed] Water can only dissolve a limited amount of solute.[removed] When water freezes, the molecules move farther apart.[removed] The water in lakes and ponds freezes from the top down.Question 29 (Multiple Choice Worth 2 points)[07.04]What is the correct balanced equation for the following equilibrium constant expression?[removed] CO2 (g) CO (g) + ½ O2 (g)[removed] CO2 (g) CO (g) + O2 (g)[removed] 2 CO2 (g) 2 CO (g) + O2 (g)[removed] 2CO (g) + O2 (g) CO2 (g)Question 30 (Multiple Choice Worth 2 points)[07.06]In the chemical reaction shown below, which element was oxidized?2K + Cl2 2KCl[removed] K, because it lost one electron[removed] K, because it gained one electron[removed] Cl, because it lost one electron[removed] Cl, because it gained one electronQuestion 31 (Multiple Choice Worth 2 points)[07.01]Which of the following correctly shows a neutralization reaction between a hydronium ion and a hydroxide ion?[removed] H+ + H2O H3O+[removed] H2O H+ + OH-[removed] H3O+ + OH- 2 H2O[removed] H2O + NH3 OH- + NH4+Question 32 (Multiple Choice Worth 2 points)[05.03]If 1.20 moles of an ideal gas occupy a volume of 18.2 L at a pressure of 1.80 atm, what is the temperature of the gas, in degrees Celsius?[removed] -125°C[removed] 59.5°C[removed] 273°C[removed] 332°CQuestion 33 (Multiple Choice Worth 2 points)[08.02] Which describes nuclear power plants?[removed] They generate power directly from nuclear reactions.[removed] They supply over 50% of the nation’s power needs.[removed] Compared to fossil fuels, they require much less fuel.[removed] They have more atmospheric pollutants compared to fossil fuels.Question 34 (Multiple Choice Worth 2 points)[05.08]A student dissolves 4.5 g of sodium chloride (NaCl) into 75 g of water (H2O). Which of the following statements is correct regarding the resulting solution when it is compared to the pure solvent?[removed] Both the vapor pressure and the boiling point will increase.[removed] The boiling temperature and the freezing temperature will decrease.[removed] The freezing temperature will increase and the vapor pressure will decrease.[removed] The vapor pressure will decrease and the boiling temperature will increase.Question 35 (Multiple Choice Worth 2 points)[05.04]When 1.5 L of methane gas combust in an excess of oxygen at standard temperature and pressure, how many liters of water vapor will be produced?CH4 (g) + 2O2 (g) CO2 (g) + 2H2O (g)[removed] 0.75 L[removed] 1.5 L[removed] 3.0 L[removed] 6.0 LQuestion 36 (Multiple Choice Worth 2 points)[07.03]Which of the following pH levels would be the most acidic?[removed] pH 2[removed] pH 5[removed] pH 8[removed] pH 12Question 37 (Multiple Choice Worth 2 points)[06.01]If you drop a 25 gram piece of metal that has a temperature of 100° Celsius into 1000 grams of water at 20°Celsius, what best describes what would occur?[removed] The temperature lost by the metal will equal the temperature gained by the water.[removed] The heat lost by the metal will equal the heat gained by the water.[removed] The final temperature will be 60°Celsius.[removed] The final temperature will be more than 60°Celsius.Question 38 (Multiple Choice Worth 2 points)[08.05]Which of the following is not true regarding carbon?[removed] Carbon 12 is radioactive.[removed] Carbon can form long chains and rings.[removed] Carbon will bond with other carbon atoms.[removed] Carbon will readily bond with hydrogen and oxygen.Question 39 (Multiple Choice Worth 2 points)[07.03]What is the pH of a 0.00750 M solution of hydrochloric acid, HCl?[removed] pH = 1.45[removed] pH = 1.93[removed] pH = 2.12[removed] pH = 3.07Question 40 (Multiple Choice Worth 2 points)[05.03]A balloon that contains 0.750 moles of gas has a volume of 16.8 L. If the balloon expands to a volume of 25.4 L at a constant pressure and temperature, how many moles of gas would the balloon contain?[removed] 0.496 mol[removed] 0.882 mol[removed] 1.13 mol[removed] 6.45 molQuestion 41 (Multiple Choice Worth 2 points)[08.04]It is widely known that fossil fuels pollute the environment and cause harmful effects. Why then are fossil fuels still being widely used?[removed] Not enough of society knows the harmful nature of fossil fuels.[removed] Cost effective alternatives are not yet ready to replace fossil fuels.[removed] Alternative fuels offer just as many environmental problems as fossil fuels.[removed] The demand for alternative fuels cannot be met by current manufacturers.Question 42 (Multiple Choice Worth 2 points)[05.01]Which phase of matter is made up of particles that are packed relatively close together, with an indefinite shape but a definite volume?[removed] gas[removed] liquid[removed] plasma[removed] solidQuestion 43 (Multiple Choice Worth 2 points)[05.05]Which of the following would be the best technique to use in order to separate a liquid from a solution?[removed] chromatography[removed] evaporation[removed] filtration[removed] simple distillationQuestion 44 (Multiple Choice Worth 2 points)[06.02]When sulfuric acid is poured on sugar the volume expands, it turns black and gets very hot. Which of the following best describes this reaction?[removed] endothermic[removed] exothermic[removed] decomposition[removed] synthesisQuestion 45 (Multiple Choice Worth 2 points)[06.04]Which of the following reactions results in a decrease in entropy?[removed] 6CO2 (g) + 6H2O (l) C6H12O6 (s) + 6O2 (g)[removed] 2NH3 (g) N2 (g) + 3H2 (g)[removed] N2O4 (g) 2NO2 (g)[removed] 2H2O2 (aq) 2H2O (l) + O2 (g)Question 46 (Multiple Choice Worth 2 points)[08.05]Carbon naturally occurs in two forms: diamond and graphite. Why do these two forms have very different properties?[removed] The key difference is that diamonds have other elements bonded within their structure.[removed] The differences are explained by the number of covalent and ionic bonds within each substance.[removed] The differences are explained by the density: graphite is very high and diamond is much lower.[removed] The differences are explained by how the carbon atoms within each substance are covalently bonded together.
