General Chemistry 2 Past Paper Review Materials (Second Semester) PDF

**Review Materials** **in** **General Chemistry 2** **(Second Semester)** Study the picture of a liquid **BELOW**. In the Kinetic Molecular Theory (KMT) of liquids and solids, why are the particles of liquids close together? A. Because they have the weakest attractive force as compared to solid...

**Review Materials** **in** **General Chemistry 2** **(Second Semester)** Study the picture of a liquid **BELOW**. In the Kinetic Molecular Theory (KMT) of liquids and solids, why are the particles of liquids close together? A. Because they have the weakest attractive force as compared to solids and gases B. Because they have stronger attractive force than those in solids and gases C. Because they have the strongest attractive force as compared to solids and gases D. Because they have a weaker attractive force than those in solids and gases  The pictures **BELOW** show a dipole-dipole and hydrogen bonding forces. How has a dipole-dipole force differed from the hydrogen bonding force? A. A dipole-dipole force results when an ion and the partial charge at the end of a polar molecule attract each other while the hydrogen bonding force has neutral polar molecules. B. A dipole-dipole force contains nonpolar substances that can be condensed to liquid and even solid if cooled enough to low temperatures while the hydrogen bonding force has positive and negative ends. C. A dipole-dipole force increases with increased molecular mass while hydrogen bonding force depends on the molecular shape. D. A dipole-dipole force exhibits polar molecules that attract each other when the positive end of one molecule is near the negative end of another while the hydrogen bonding force shows an attractive interaction between a hydrogen atom bonded to an electronegative F, O, or N atom and an unshared electron pair of another nearby electronegative atom. *In a laboratory, four students---Anna, Ben, Clara, and David---are investigating different types of intermolecular forces in various substances. They are provided with the following substances: H₂O (water), C₂H₆ (ethane), NH₃ (ammonia), and NaCl (sodium chloride). Each student is tasked with identifying the predominant intermolecular force present in each substance.* Which student has **CORRECTLY** described the predominant intermolecular force in their assigned substance? A. Anna describes the predominant intermolecular force in H₂O as London dispersion forces. B. Ben describes the predominant intermolecular force in C₂H₆ as hydrogen bonding. C. Clara describes the predominant intermolecular force in NH₃ as dipole-dipole interactions. D. David describes the predominant intermolecular force in NaCl as ion-dipole interactions.  Below is a picture of the viscosity of a liquid. Which statement is **TRUE** about it? A. The stronger the intermolecular forces, the more viscous the liquid is. B. The smaller the molecules, the more viscous the liquid is. C. The higher the temperature, the more viscous the liquid is. D. The normal temperature, the more viscous the liquid is. A researcher is analyzing two liquids, A and B, under identical conditions. Liquid A has stronger intermolecular forces compared to Liquid B. During the experiment, the researcher observes the following: - **Liquid A forms small, spherical droplets on a surface, while Liquid B spreads out more.** - **Liquid A has a higher boiling point than Liquid B.** - **Liquid B evaporates faster than Liquid A.** Based on these observations, which conclusion **MOST ACCURATELY** describes the effect of intermolecular forces on the properties of liquids? A. Liquid A's stronger intermolecular forces result in lower surface tension and higher vapor pressure.\ B. Liquid A's stronger intermolecular forces result in higher surface tension and higher boiling point.\ C. Liquid A's stronger intermolecular forces result in lower viscosity and lower molar heat of vaporization.\ D. Liquid A's stronger intermolecular forces result in higher vapor pressure and faster evaporation. What you have seen **on page 4** are the properties of water. Which of the following statements **BEST** explains it? A. Water has low surface tension. B. It has a high boiling point which is why it is liquid at room temperature. C. The density of liquid water is less than the density of solid water or ice. D. It has a low heat of vaporization. *During an exceptionally cold winter, a municipal water supply system experienced an unexpected surge in water pressure in several pipelines, leading to burst pipes. This anomaly occurred even though the water temperature within the pipes remained just above freezing point. As an expert called in to investigate, you need to provide a detailed explanation of how the molecular structure and intermolecular forces of water contributed to this incident.* Which of the following **BEST** explains the phenomenon? A. The hydrogen bonds in water molecules became weaker at low temperatures, causing the water to expand and increase the pressure within the pipes. B. The polarity of water molecules caused them to align in a way that decreased the volume of water, leading to an increase in pressure within the pipes. C. The formation of a crystalline structure within water at low temperatures increased the density of water, leading to a rise in pressure that burst the pipes. D. The hydrogen bonds in water molecules became more structured at low temperatures, causing the water to expand and increase the pressure within the pipes. *A researcher is studying how water interacts with different substances. During an experiment, the researcher observes the following:* - ***Water droplets on a clean glass surface spread out into a thin layer.*** - ***On a wax-coated surface, the water forms round droplets instead.\ The researcher hypothesizes that this behavior is due to the molecular properties of water and its interactions with other surfaces.*** **Question:** Which of the following **BEST** explains the observed phenomena? A. **Water molecules exhibit strong covalent bonds within the molecule, preventing interaction with other substances.**\ B. **The hydrogen bonding between water molecules is stronger than the adhesive forces between water and wax, leading to droplet formation.**\ C. **The polarity of water molecules allows them to bond ionically with glass, causing the spreading behavior.**\ D. **Water molecules are non-polar and, therefore, do not interact with wax surfaces.**  ***A chunk of solid lead (Pb) is dropped into a pool of molten (liquid) lead. The solid lead sinks to the bottom of the pool.*** Based on the pictures and the above situationer, what predicts you about the density of each material? A. The densities are the same. B. The density of the liquid is greater than that of the solid. C. The density of the solid is greater than that of the liquid. D. The density of the molten lead is greater than that of the solid. Study the phase diagram of water. Which statement does **BEST** interpret it?  A. The regions in the diagram are labeled solid and liquid. B. The three phases in equilibrium along the two lines are also shown. C. The three-way intersection of all three phases coexists in equilibrium at the triple point of water. D. The triple-point temperature of the water is 0.0096^ᵒ^C, and the triple-point pressure is 0.007 atm. *Maria is a chemist studying phase transitions of substances under different conditions. During her experiment, she observed a sealed container of water placed under conditions where the temperature is 100°C and the pressure is 0.5 atm. She then compares this with another experiment involving carbon dioxide at - 80°C and 1 atm. She refers to the phase diagrams of water and carbon dioxide to interpret their respective states.* Which of the following **BEST** interprets the behavior of the two substances when subjected to an increase in pressure at their respective temperatures? A. Water is in the liquid state, carbon dioxide is in the gaseous state, and both substances remain in their initial phase when pressure increases.\ B. Water is in the liquid state, carbon dioxide is in the solid state, and both substances undergo a phase transition when pressure increases.\ C. Water is in the gaseous state, carbon dioxide is in the solid state, and only water undergoes a phase transition when pressure increases.\ D. Water is in the gaseous state, carbon dioxide is in the solid state, and only carbon dioxide undergoes a phase transition when pressure increases. Study the phase diagram **BELOW**. Which statement **BEST** elucidates the cooling curve of a substance? A. There are cases where liquids are cooled below their normal freezing points before freezing occurs. B. The curve shows when there are few nuclei (such as suspended impurities) on which liquid particles cannot crystallize. C. The broken line represents the condition of superwarming. D. When a supercooled liquid begins to freeze, its temperature lowers back to the normal freezing point where freezing is completed. *A scientist is conducting an experiment to determine the heating and cooling curve of a substance. They start by heating the substance from a solid state and continue to increase the temperature until the substance becomes a gas. During the experiment, they record the temperature changes over time and plot the heating curve. Similarly, the scientist then cools the substance from the gas state back to a solid state and plots the cooling curve.* Based on the heating and cooling curves obtained, determine which of the following statements accurately explains the phase changes and the energy changes associated with them. A. The substance absorbs energy during the melting and boiling phases, causing an increase in temperature. B. The temperature of the substance remains constant during the melting and boiling phases, indicating a change in potential energy rather than kinetic energy. C. The substance releases energy during the condensation and freezing phases, causing a decrease in temperature. D. The temperature of the substance decreases steadily during the freezing phase, indicating a change in kinetic energy rather than potential energy.  Below are the pictures of a solution that is prepared by dissolving 4.00 g of sodium hydroxide (NaOH) in 100.00 g of water. The volume of the resulting solution is 102.00 mL. What is the mole fraction of the NaOH? **Note:** *Round off your answer to the correct number of significant figures.* A. 0.0179 C. 0.00178 B. 0.0180 D. 0.00177 If 28.5 g of calcium hydroxide Ca(OH)~2~ is dissolved in enough water to make 185 g of solution, what is the percent by mass of Ca(OH)~2~ in the solution? **Note:** *Round off your answer to the correct number of significant figures.* A. 15.4% C. 15.2% B. 15.3% D. 15.5% Above is a picture of an aqueous solution (soln) of phosphoric acid (H~3~PO~4~). Calculate the molality of 35.4 percent (by mass) of it whose molar mass is 98.00 g. **Note:** *Round off your answer to the correct number of significant figures.* A. 5.58 *m C. 5.56 m* B. 5.57 *m D. 5.59 m* Calculate the mass (in grams) of calcium nitrate \[Ca(NO~3~)~2~\] that can be produced by reacting 136 mL of 4.00 *M* nitric acid (HNO~3~) with excess calcium hydroxide \[Ca(OH)~2~\]. (molar mass of \[Ca(NO~3~)~2~\] = 164.1 g/mol) Note: **Note:** *Round off your answer to the correct number of significant figures.* A. 44.5 g C. 44. 8 g B. 44.7 g D. 44.6 g How many liters of 0.53 *M* HCl is required to neutralize 0.78 g of sodium carbonate (Na~2~CO~3~)? (molar mass of Na~2~CO~3~ = 105.99 g/mol) **Note:** *Round off your answer to the correct number of significant figures.* A. 0.029 L C. 0.028 L B. 0.026 L D. 0.027 L A scientist is tasked with designing a new antifreeze solution to use in extremely cold environments. She prepares four solutions using the same solvent but different concentrations of solutes. The solutions are tested to determine their freezing points: - **Solution A: 0.1 mol/L** - **Solution B: 0.5 mol/L** - **Solution C: 1.0 mol/L** - **Solution D: 2.0 mol/L** Based on your understanding of colligative properties, which of the following **BEST** describes the effect of increasing solute concentration on the freezing point of these solutions?\ A. The freezing point of the solution increases as solute concentration increases because the solute particles absorb more heat.\ B. The freezing point of the solution decreases as solute concentration increases because the solute particles disrupt the formation of the solvent\'s solid structure.\ C. The freezing point remains the same regardless of solute concentration because colligative properties depend only on the type of solute.\ D. The freezing point of the solution fluctuates unpredictably with solute concentration due to variations in solute particle interactions.  Study the picture **BELOW**. How is the electrolyte solution contrasted with the nonelectrolyte solution? A. By looking at the solutes that dissociate into ions when dissolved and can conduct electricity B. By examining the solutes that do not dissociate into ions when dissolved and therefore do not conduct electricity C. By testing the solutes that dissociate into ions when dissolved and can conduct electricity D. By measuring the solutes that do dissociate into ions when dissolved and therefore do not conduct electricity  A soln is prepared by dissolving 2.40 g of biphenyl, C~12~H~10~ (molar mass = 154 g/mol), in 75.0 g benzene. What is the boiling point of the soln? **Note:** *Round off your answer to the correct number of significant figures.* A. 80.4ᵒC C. 80.6ᵒC B. 80.5ᵒC D. 80.7ᵒC Refer to question 14. What is its freezing point? *Round off your answer to the correct number of significant figures.* A. 4.42ᵒC C. 4.45ᵒC B. 4.44ᵒC D. 4.43ᵒC Calculate the boiling point of soln containing 4.27 g of sucrose (C~12~H~22~O~11~) and 50.0 g of water. (molar mass of (C~12~H~22~O~11~) = 342 g/mol, *K~f~* of H~2~O = 1.86°C/m, *K~b~* of H~2~O = 0.52°C/m) What is its freezing point? **Note:** *Round off your answer to the correct number of significant figures.* A. 100.13°C C. 100.14°C B. 100.12°C D. 100.15°C When 4.35 g of ethylene glycol (C~2~H~6~O~2~) is dissolved in 100 g of water, the resulting solution has a freezing point of -- 1.31°C. Calculate the molar mass of C~2~H~6~O~2~. Note: *Round off your answer to the correct number of significant figures.* A. 0.704 m C. 0.700 m B. 0.703 m D. 0.702 m Biochemists have discovered more than 400 mutant varieties of hemoglobin, the blood protein that carries oxygen throughout the body. A physician studying a variety associated with a fatal disease first finds its molar mass (*M*). He/She dissolves 21.5 mg of the protein in water at 5.0°C to make 1.50 mL of soln and measures an osmotic pressure of 3.61 torr. What is the molar mass of this variety of hemoglobin? Note: *Round off your answer to the correct number of significant figures.* A. 6. 88 x 10^4^ g/mol C. 6. 90 x 10^4^ g/mol B. 6. 89 x 10^4^ g/mol D. 6. 91 x 10^4^ g/mol In a study designed to prepare new gasoline-resistant coatings, a polymer chemist dissolves 6.053 g of poly (vinyl alcohol) in enough water to make 100.0 mL of solution. At 25°C, the osmotic pressure of this solution is 0.272 atm. What is the molar mass of the polymer sample? Note: *Round off your answer to the correct number of significant figures.* A. 5.6 X 10^3^ g/mol C. 5.4 X 10^3^ g/mol B. 5.7 X 10^3^ g/mol D. 5.5 X 10^3^ g/mol  How would you prepare a 0.1*M* HCl soln from 10 mL of a 0.5 *M* HCl stock soln? A. By using a pipet/pipette, measure 10 mL of 0.5*M* HCl and place the soln in a 50-mL volumetric flask B. By adding distilled water to the flask up to the etched line C. By diluting the acid to exactly 50 mL of 0.1*M* HCl D. All of the above Which of the following statements **CORRECTLY** explicates the First Law of Thermodynamics? A. It states the entropy of a system approaches a constant value as the temperature approaches absolute zero. B. It states if the physical process is irreversible, the combined entropy of the system and the environment must increase. C. It states that energy cannot be created nor destroyed; it can only be converted from one form to another. D. It states every nonequilibrium state of a system or local subsystem for which entropy is well defined must be equipped with a metric in state space concerning which the irreversible component of its time evolution is in the direction of steepest entropy ascent compatible with the conservation constraints. *A refrigeration technician is testing a cooling system where a refrigerant absorbs heat from inside a refrigerator and transfers it to the surroundings.* Based on the first law of thermodynamics, what must happen for the refrigerant to perform this task effectively? A. The system must receive work input from a compressor.\ B. The refrigerant must generate heat by itself.\ C. The heat absorbed inside the refrigerator must exceed the heat released outside.\ D. The refrigerant must cool to absolute zero. A factory is designing a steam engine for powering a generator. The engineers claim that their design can convert all the absorbed heat into work without any waste. Based on the first law of thermodynamics, which of the following statements is **MOST NEARLY ACCURATE**?\ A. Their claim is valid because energy cannot be created or destroyed.\ B. Their claim violates the first law because some energy must remain as internal energy.\ C. Their claim violates the first law because some heat must always be expelled.\ D. Their claim is valid if the engine is perfectly insulated.  What statement about enthalpy is **TRUE**? A. Enthalpy, *H,* is equal to the amount of heat flow in a system with constant pressure Q*~P~*. B. It is a measure of the randomness or disorder of a system. C. It is related to the natural log of the number of microstates. D. It shows the probability of occurrence of a particular distribution (state) depends on the number of ways (microstates) in which the distribution can be achieved. ### *During a laboratory experiment, a student mixes 50 mL of 1 M hydrochloric acid (HCl) with 50 mL of 1 M sodium hydroxide (NaOH) in a polystyrene cup calorimeter. The temperature of the solution rises from 25°C to 35°C. The student concludes that the reaction is exothermic.* What is the most appropriate explanation for the observed temperature increase? A. The reaction releases heat to the surroundings, resulting in an increase in the temperature of the solution. B. The temperature increase is due to the endothermic absorption of heat from the surroundings. C. The heat released during the reaction is absorbed by the polystyrene cup. D. The temperature increase is caused by the evaporation of water in the solution. *A researcher is investigating the enthalpy change of combustion for a hydrocarbon fuel. In the experiment, a fuel sample is burned in a bomb calorimeter, and the temperature of the surrounding water increases significantly. The researcher calculates the heat released during combustion but notices the value is lower than the theoretical enthalpy of combustion.* Which factor is most likely causing the discrepancy in the calculated enthalpy change? A. Incomplete combustion of the hydrocarbon fuel resulted in less heat release.\ B. The water absorbed heat, lowering the total energy released.\ C. The calorimeter was poorly insulated, causing heat loss to the surroundings.\ D. The researcher added too much fuel to the calorimeter, increasing the calculated enthalpy change. Calculate the change in internal energy when 2 moles of carbon monoxide (CO) are converted to 2 moles of CO~2~ at 1 atm and 25ᵒC. **Note:** *Round off your answer to the correct number of significant figures.* **2CO~(*g)*~ + O~2*(g)*~ 2CO~2*(g)*~ ∆*H* = - 566.0 kJ/mol** A. - 563.5 kJ/mol C. -- 562.7 kJ/mol B. -- 564.4 kJ/mol D. D. -- 565.9 kJ/mol Two gaseous pollutants that form in auto exhaust are CO and NO. An environmental chemist is studying ways to convert them to less harmful gases through the following equations: **CO~(g)~ + NO~(g)~ → CO~2(g)~ + ½ N~2(g)~ Δ*H* = ?** Given the following information, calculate the unknown **Δ*H*:** **Equation A: CO~(g)~ + ½ O~2(g)~ → CO~2(g)~ Δ*H*~A~ = - 283.0 kJ** **Equation B: N~2(g)~ + O~2(g)~ → 2NO~(g)~ Δ*H*~A~ = - 180.6 kJ** A. CO~(g)~ + NO~(g)~ → CO~2(g)~ + ½ N~2(g)~ Δ*H* = - 373.3 kJ B. CO~(g)~ + NO~(g)~ → CO~2(g)~ + ½ N~2(g)~ Δ*H* = - 373.4 kJ C. CO~(g)~ + NO~(g)~ → CO~2(g)~ + ½ N~2(g)~ Δ*H* = - 373.2 kJ D. CO~(g)~ + NO~(g)~ → CO~2(g)~ + ½ N~2(g)~ Δ*H* = - 373.5 kJ Nitrogen oxides undergo many interesting reactions in the environment and in industry. Given the following information, calculate Δ*H* for the overall equation **2NO~2(g)~ + ½ O~2(g)~** **→ N~2~O~5(s)~:** N~2~O~5(s)~ → 2NO~(g)~ + 3/2 O~2(g)~ **Δ*H* = 223.7 kJ** NO~(g)~ + 1/2 O~2(g)~ → NO~2(g)~ **Δ*H* = - 57.1 kJ** A. 2NO~2(g)~ + ½ O~2(g)~ → N~2~O~5(s)~ Δ*H* = - 109.5 kJ B. 2NO~2(g)~ + ½ O~2(g)~ → N~2~O~5(s)~ Δ*H* = 109.5 kJ C. 2NO~2(g)~ + ½ O~2(g)~ → N~2~O~5(s)~ Δ*H* = - 108.5 kJ D. 2NO~2(g)~ + ½ O~2(g)~ → N~2~O~5(s)~ Δ*H* = 108.5 kJ A factory is optimizing the production of ammonia using the Haber process:\ **N2​(g)+3H2​(g)↔2NH3​(g)**\ The factory manager observes that the reaction rate is slower than expected. To address this, the team evaluates several factors. They note the following conditions: - Temperature: 300°C - Pressure: 50 atm - Catalyst: Iron catalyst in use Which of the following adjustments would **MOST EFFECTIVELY** increase the rate of the reaction while maintaining safety and efficiency? A. Increase the temperature to 450°C.\ B. Decrease the pressure to 30 atm.\ C. Double the amount of nitrogen gas introduced into the system.\ D. Replace the iron catalyst with a more effective catalyst. In the integrated rate law of reactions, how does a zero-order reaction differ from a first-order reaction? A. A \"second-order reaction\" in the context of an integrated rate law means that the rate of a chemical reaction is completely independent of the concentration of the reactants while a \"first-order reaction\" in the context of an integrated rate law means that the rate of a chemical reaction is directly proportional to the concentration of only one reactant, resulting in a linear relationship when plotting the natural logarithm of reactant concentration against time. B. A \"zero-order reaction\" in the context of an integrated rate law means that the rate of a chemical reaction is completely independent of the concentration of the reactants while a \"second-order reaction\" in the context of an integrated rate law means that the rate of a chemical reaction is directly proportional to the concentration of only one reactant, resulting in a linear relationship when plotting the natural logarithm of reactant concentration against time. C. A \"zero-order reaction\" in the context of an integrated rate law means that the rate of a chemical reaction is completely independent of the concentration of the reactants while a \"first-order reaction\" in the context of an integrated rate law means that the rate of a chemical reaction is directly proportional to the concentration of only one reactant, resulting in a linear relationship when plotting the natural logarithm of reactant concentration against time. D. A \"first-order reaction\" in the context of an integrated rate law means that the rate of a chemical reaction is completely independent of the concentration of the reactants while a \"zero-order reaction\" in the context of an integrated rate law means that the rate of a chemical reaction is directly proportional to the concentration of only one reactant, resulting in a linear relationship when plotting the natural logarithm of reactant concentration against time. Which of the following statements **BEST** explains the fundamental idea(s) of the collision theory of molecules? A. A molecular collision is effective if it leads to the formation of products. B. A molecular collision is ineffective if it decreases the formation of products. C. A molecular collision is effective if it does not lead to the formation of products. D. A molecular collision is ineffective if it increases the formation of products. *In a car engine, fuel and oxygen react to produce energy in a combustion reaction. Various factors can influence the efficiency of this reaction.* Which of the following factors is likely to increase the rate of the combustion reaction inside the engine by affecting molecular collisions? A. Decreasing the temperature of the engine B. Reducing the concentration of oxygen C. Increasing the surface area of the fuel D. Adding an inert gas to the fuel mixture *In a laboratory, a student conducts an experiment in which hydrochloric acid (HCl) reacts with sodium hydroxide (NaOH) in a beaker. The student observes the reaction to determine the impact of various conditions on the reaction rate.* Which change will **MOST LIKELY** lead to an increased reaction rate between HCl and NaOH due to enhanced molecular collisions? A. Diluting the NaOH solution B. Heating the mixture C. Using a weaker acid instead of HCl D. Decreasing the concentration of HCl  What statement **BELOW CORRECTLY** expounds the activation energy? A. The energy of the products is equal to the energy of the reactants. B. The energy of the reactants is inversely proportional to the energy of the products. C. The energy lost in the reactions is directly proportional to the energy gained. D. The minimum energy is needed by the reactants to form the products. *During an industrial process, the production team observes that a specific reaction involving the conversion of substance A to substance B is too slow at the operating temperature of 300 K. They decide to add a catalyst to speed up the reaction.* Based on this information, which of the following statements accurately explains the role of the catalyst in this scenario? A. The catalyst increases the activation energy required for the reaction. B. The catalyst provides an alternative pathway with a lower activation energy. C. The catalyst directly increases the temperature of the reaction mixture. D. The catalyst changes the equilibrium position of the reaction. *A biochemist is studying an enzyme-catalyzed reaction where substrate S is converted to product P. Without the enzyme, the activation energy for the reaction is 150 kJ/mol. With the enzyme, the activation energy is reduced to 75 kJ/mol.* If the reaction is performed at a constant temperature, how does the presence of the enzyme affect the reaction rate? A. The enzyme increases the activation energy required for the reaction. B. The enzyme increases the reaction rate by providing thermal energy to the reactants. C. The enzyme increases the reaction rate by lowering the activation energy. D. The enzyme shifts the equilibrium position to favor the formation of product P. Which of the following **BEST** differentiates how homogeneous and heterogeneous catalysts interact with reactants? A. Homogeneous catalysts uniformly interact with reactants while heterogeneous catalysts oppositely interact with them. B. Homogeneous catalysts oppositely interact with reactants while heterogeneous catalysts uniformly interact with them. C. Homogeneous catalysts mix with reactants while heterogeneous catalysts uniformly interact with them. D. Homogeneous catalysts interact with reactants out of sequence while heterogeneous catalysts dislike reactants.