last chemistry test .. Really need this test to be aced !

Question 1 (Multiple Choice Worth 2 points)

[07.06]<object:standard:sc.912.p.8.10>In the chemical reaction shown below, which element was reduced?

Zn + H₂SO₄  ZnSO₃+ H₂O

[removed] Zn, because it gained 2 electrons

[removed] Zn, because it lost 2 electrons

[removed] S, because it gained 2 electrons

[removed] S, because it lost 2 electrons

 

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Question 2 (Multiple Choice Worth 2 points)

[05.03]<object:standard:sc.912.p.12.10>If 1.6 moles of an ideal gas are at a temperature of 25°C and a pressure of 0.91 atm Hg, what volume would the gas occupy, in liters?

[removed] 0.28 L

[removed] 3.0 L

[removed] 36 L

[removed] 43 L

 

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Question 3 (Multiple Choice Worth 2 points)

[05.01]<object:standard:sc.912.p.8.1>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] solid

 

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Question 4 (Multiple Choice Worth 2 points)

[06.04]<object:standard:sc.912.p.10.2>Which of the following circumstances will result in a reaction that is spontaneous only at low 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 change

 

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Question 5 (Multiple Choice Worth 2 points)

[08.03]<object:standard:sc.912. l.17.19=””>Which of the following best describes the forces that create natural gas?

[removed] Heat from the Earth’s 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 beneath the Earth’s surface heats underground water into steam.

[removed] Heat energy is released during nuclear fission and steam is produced to turn a turbine.

 

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Question 6 (Multiple Choice Worth 2 points)

[07.06]<object:standard:sc.912.p.8.8>Which of the following chemical reactions is an oxidation-reduction reaction?

[removed] Fe₂O₃ + 3CO  2Fe + 3CO₂

[removed] MgSO₄ + 2KI K₂SO₄ + MgI₂

[removed] NaNO₃ + KCl  KNO₃ + NaCl

[removed] Cu(NO₃)₂ + 2HBr CuBr₂ + 2HNO₃

 

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Question 7 (Multiple Choice Worth 2 points)

[08.01]<object:standard:sc.912.p.10.11, sc.912.p.10.12=””>Which of the following represents a balanced nuclear equation showing Bismuth-212 undergoing alpha decay followed by beta decay?

[removed]    +   x- + 

[removed]  +   +   x-

[removed]    +    + 

[removed]    +    + 

 

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Question 8 (Multiple Choice Worth 2 points)

[07.03]<object:standard:sc.912.p.8.11> What is the concentration of hydronium ions in a solution with a pH = 3.9?

[removed] 4.14 × 10^-2

[removed] 7.80 × 10^-3

[removed] 1.26 × 10^-4

[removed] 3.00 × 10^-5

 

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Question 9 (Multiple Choice Worth 2 points)

[07.02]<object:standard:sc.912.p.8.8, sc.912.p.8.11=””>Which of the following is the salt in the Brønsted-Lowry neutralization reaction?

HBr + NaHCO₃  H₂CO₃ + NaBr

[removed] HBr

[removed] NaHCO₃

[removed] H₂CO₃

[removed] NaBr

 

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Question 10 (Multiple Choice Worth 2 points)

[05.07]<object:standard:sc.912. p.8.9.=””>How many grams of potassium nitrate (KNO₃) would form if 2.25 liters of a 1.50 molar lead nitrate Pb(NO₃)₂ solution reacts with 1.15 liters of a 2.75 molar potassium chromate K₂CrO₄solution? 

Pb(NO₃)₂ + K₂CrO₄  PbCrO₄ + 2KNO₃

[removed] 108 g

[removed] 681 g

[removed] 639 g

[removed] 362 g

 

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Question 11 (Multiple Choice Worth 2 points)

[06.04]<object:standard:sc.912.p.10.6>On a potential energy diagram for the following processes, which of the following has a decrease in entropy?

[removed] ice melts

[removed] water freezes

[removed] water boils

[removed] sublimation of dry ice into carbon dioxide gas

 

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Question 12 (Multiple Choice Worth 2 points)

[07.02]<object:standard:sc.912.p.8.8, sc.912.p.8.11=””>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 M

 

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Question 13 (Multiple Choice Worth 2 points)

[08.04]<object:standard:sc.912.n.4.2>What is the purpose of environmental remediation?

[removed] to restore water to its original purity levels

[removed] to make the most of currently used technologies and resources

[removed] to remove pollution or contamination from the environment

[removed] to reuse materials that would otherwise go to waste

 

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Question 14 (Multiple Choice Worth 2 points)

[06.05]<object:standard:sc.912.n.3.5, sc.912.p.12.12=””>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.

 

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Question 15 (Multiple Choice Worth 2 points)

[07.04]<object:standard:sc.912.p.12.13>What is the correct balanced equation for the following equilibrium constant expression?

[removed] CO_{2 (g)}  CO _(g) + ½ O_{2 (g)}

[removed] CO_{2 (g)}  CO _(g) + O_{2 (g)}

[removed] 2 CO_{2 (g)}  2 CO _(g) + O_{2 (g)}

[removed] 2CO _(g) + O_{2 (g)}  CO_{2 (g)}

 

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Question 16 (Multiple Choice Worth 2 points)

[08.03]<object:standard:sc.912. l.17.19=””>Which of the following natural resources is considered renewable?

[removed] biofuel

[removed] natural gas

[removed] nuclear power

[removed] oil

 

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Question 17 (Multiple Choice Worth 2 points)

[06.05]<object:standard:sc.912.n.3.5, sc.912.p.12.12=””>According to the collision theory and model created to explain the collision theory, what two factors must be satisfied for a given collision to be successful and result in the production of products?

[removed] Correct molecular shape and momentum.

[removed] Correct position and maximum potential.

[removed] Correct density and threshold velocity.

[removed] Correct orientation and sufficient energy.

 

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Question 18 (Multiple Choice Worth 2 points)

[08.02]<object:standard:sc.912.p.10.11> 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.

 

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Question 19 (Multiple Choice Worth 2 points)

[06.02]<object:standard:sc.912.p.10.7>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] synthesis

 

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Question 20 (Multiple Choice Worth 2 points)

[05.08]<object:standard:sc.912.p.8.2.>Which of the following solutions will have the greatest colligative effect?

[removed] 2 moles of glucose (C₆H₁₂O₆) dissolved in 1.0 kg of water (H₂O)

[removed] 1.5 moles of sodium chloride (NaCl) dissolved in 1000.0 kg of water (H₂O)

[removed] 0.75 moles of calcium fluoride (CaF₂) dissolved in 500.0 g of water (H₂O)

[removed] 0.50 moles of carbon dioxide (CO₂) dissolved in 250.0 g of water (H₂O)

 

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Question 21 (Multiple Choice Worth 2 points)

[08.06]<object:standard:sc.912. l.16.10=””>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.

 

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Question 22 (Multiple Choice Worth 2 points)

[05.01]<object:standard:sc.912.p.8.1, sc.912.p.8.2=””>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.

 

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Question 23 (Multiple Choice Worth 2 points)

[05.06]<object:standard:sc.912.l.18.12>In a body of water, the surface tension caused by the attraction between water molecules is strong. Which of the following is a consequence of this property?

[removed] Water is considered to be a universal solvent.

[removed] When water freezes, the molecules move farther apart.

[removed] Only a limited amount of solute can be dissolved in a sample of water.

[removed] Objects with a higher density than water can be observed floating on water.

 

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Question 24 (Multiple Choice Worth 2 points)

[07.05]<object:standard:sc.912.p.12.13>What would happen to the following endothermic reaction that is in equilibrium if heat is added?

N₂O_{4 (g)}  2 NO_{2 (g)}

[removed] The reaction would not be affected

[removed] The equilibrium would shift to the left

[removed] The equilibrium would shift to the right

[removed] The product concentration would equal the reactants

 

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Question 25 (Multiple Choice Worth 2 points)

[05.03]<object:standard:sc.912.p.12.10>A sample of gas has a volume of 2.4 L and a pressure of 1.2 atm. What would the pressure of the same gas sample be if the volume is reduced to 1.8 L at a constant temperature?

[removed] 0.90 atm

[removed] 1.6 atm

[removed] 5.2 atm

[removed] 3.6 atm

 

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Question 26 (Multiple Choice Worth 2 points)

[07.03]<object:standard:sc.912.p.8.11>Which is not true regarding the pH scale?

[removed] The neutral pH at 25°C is 7.0.

[removed] Bases have a pH greater than 7.0.

[removed] The pH scale measures the hydronium ion concentration in solution.

[removed] When the concentration of hydroxide ions increases, the pH decreases.

 

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Question 27 (Multiple Choice Worth 2 points)

[06.04]<object:standard:sc.912.p.10.2>Which of the following reactions results in a decrease in entropy?

[removed] CaCO_{3 (s)}  CaO _(s) + CO_{2 (g)}

[removed] N₂O₄ (g)  2NO_{2 (g)}

[removed] CaO _(s) + SO_{3 (g)}  CaSO_{4 (s)}

[removed] 2NH_{3 (g)}  N_{2 (g)} + 3H_{2 (g)}

 

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Question 28 (Multiple Choice Worth 2 points)

[07.06]<object:standard:sc.912.p.8.10>What is the oxidation number of sulfur (S) in sulfuric acid (H₂SO₄)?

[removed] -6

[removed] +2

[removed] +4

[removed] +6

 

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Question 29 (Multiple Choice Worth 2 points)

[06.04]<object:standard:sc.912.p.10.6>For an exothermic reaction, which of the following conditions must be true for all products?

[removed] The change in enthalpy is positive and potential energy diagram is higher.

[removed] The change in enthalpy is negative and potential energy diagram is higher.

[removed] The change in enthalpy is positive and potential energy diagram is lower.

[removed] The change in enthalpy is negative and potential energy diagram is lower.

 

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Question 30 (Multiple Choice Worth 2 points)

[05.04]<object:standard:sc.912.p.12.10, sc.912.p.8.9=””>When 7.50 L of sulfur trioxide are produced by the reaction of sulfur dioxide in an excess of oxygen at standard temperature and pressure, how many liters of sulfur dioxide were used? 

2SO_{2 (g)} + O_{2 (g)}  2SO_{3 (g)}

[removed] 3.75 L

[removed] 5.00 L

[removed] 7.50 L

[removed] 15.0 L

 

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Question 31 (Multiple Choice Worth 2 points)

[06.01]<object:standard:sc.912.p.10.2>If you drop a 150 gram piece of metal that has a temperature of 125°Celsius into 1000 grams of water at 20°Celsius, what best describes what would occur?

[removed] More heat will be lost by the metal than gained by the water.

[removed] The temperature of the water will be greater than the amount of heat lost by the metal.

[removed] The temperature change of the metal will equal the temperature change of the water.

[removed] The heat lost by the metal will equal the heat gained by the water.

 

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Question 32 (Multiple Choice Worth 2 points)

[06.03]<object:standard:sc.912.p.10.5>Which is not true regarding the specific heat of water?

[removed] The specific heat of water explains capillary action.

[removed] The specific heat of water is 4.18 J/(°C × g).

[removed] Water is useful as an engine coolant because of its high specific heat

[removed] The specific heat of water is the reason islands have milder climates.

 

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Question 33 (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 distillation

 

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Question 34 (Multiple Choice Worth 2 points)

[08.01]<object:standard:sc.912.p.10.11, sc.912.p.10.12=””>Which statement is not correct regarding radiation?

[removed] Nuclear reactions arise from an atom’s nucleus.

[removed] Alpha, Beta, and Gamma are types of radiation.

[removed] Most of the earth’s nuclear energy comes from the Sun.

[removed] Radioactive elements have an unbalanced number of protons and electrons.

 

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Question 35 (Multiple Choice Worth 2 points)

[08.05]<object:standard:sc.912.p.8.12>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.

 

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Question 36 (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% NaCl

 

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Question 37 (Multiple Choice Worth 2 points)

[06.02]<object:standard:sc.912.p.10.6>On an endothermic potential energy diagram, what is true for all products?

[removed] The products are at the same energy level as the reactants.

[removed] The products are at a lower energy level than the reactants.

[removed] The products are at a higher energy level than the reactants.

[removed] The products do not have energy.

 

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Question 38 (Multiple Choice Worth 2 points)

[06.03]<object:standard:sc.912.p.10.2, sc.912.p.10.5=””>125.0 g of an unknown substance is heated to 97.0°C. It is then placed in a calorimeter than contains 250g of water with an initial temperature of 20.0°C. The final temperature reached by the calorimeter is 23.5°C. What is the specific heat of the unknown substance? The specific heat of water is 4.18 J/ (°C × g).

[removed] 0.285 J/ (°C × g)

[removed] 0.398 J/ (°C × g)

[removed] 0.729 J/ (°C × g)

[removed] 1.24 J/ (°C × g)

 

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Question 39 (Multiple Choice Worth 2 points)

[06.01]<object:standard:sc.912.p.10.2>How would a system which exchanges energy but does not exchange matter between the system and the surroundings be classified?

[removed] an open system

[removed] an isolated system

[removed] a closed system

[removed] an integrated system

 

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Question 40 (Multiple Choice Worth 2 points)

[07.05]<object:standard:sc.912.p.12.13>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.

 

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Question 41 (Multiple Choice Worth 2 points)

[08.04]<object:standard:sc.912.l.17.15>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, farming

 

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Question 42 (Multiple Choice Worth 2 points)

[08.05]<object:standard:sc.912.p.8.12>A carbon atom has a strong tendency to do which of the following?

[removed] double bond with electrons

[removed] receive electrons

[removed] donate electrons

[removed] share electrons

 

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Question 43 (Multiple Choice Worth 2 points)

[07.01]<object:standard:sc.912.p.8.11>What is the difference between a strong acid and a weak acid?

[removed] A strong acid has a higher pH than a weak acid.

[removed] A strong acid is 100% ionized, a weak acid is less than 100% ionized.

[removed] A strong acid is diprotic or triprotic, a weak acid is monoprotic.

[removed] A strong acid has a greater concentration of hydroxide ions compared to a weak acid.

 

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Question 44 (Multiple Choice Worth 2 points)

[07.01]<object:standard:sc.912.p.8.11>Which of the following is not true of acids?

[removed] Acids are corrosive.

[removed] Dilute acids feel slippery.

[removed] Acids have a distinctly sour taste.

[removed] Acids have more hydronium ions than hydroxide ions

 

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Question 45 (Multiple Choice Worth 2 points)

[07.04]<object:standard:sc.912.p.12.13>Which answer does not describe the following reaction?

NO _(g) + O_{2 (g)}  2 NO_{2 (g)}

[removed] The reaction is in dynamic equilibrium.

[removed] The reaction does not go to completion.

[removed] The reaction is reversible.

[removed] The concentration of reactants and products will be equal.

 

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Question 46 (Multiple Choice Worth 2 points)

[08.02]<object:standard:sc.912.p.10.11>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.