Chemical Reactions Practice Questions PDF

Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 1. A chemical change that occurs when two or more substances combine to form a new substance. A. Activation Energy B. Chemical Kinetics C. Chemical Reaction D. Product  Choose the letter of...

Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 1. A chemical change that occurs when two or more substances combine to form a new substance. A. Activation Energy B. Chemical Kinetics C. Chemical Reaction D. Product  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 2. The measure of the change in the concentration of the reactants and the products. A. Activation Energy B. Activation Rate C. Chemical Reaction D. Concentration  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 3. The substance or particles that enter into and is altered in the course of a chemical reaction. A. Catalyst B. Enzyme C. Product D. Reactant  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 4. The number of particles present in a given volume of solution. A. Catalyst B. Concentration C. Product D. Temperature  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 5. The measure of how fast or slow a reaction happens. A. Activation Energy B. Collision Theory C. Particle Size D. Rate of Reaction  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 6. Condition that needs to be met for a chemical reaction to occur. A. Substance must be homogeneous. B. Temperature should be kept constant. C. Particles should maintain a certain distance to each other. D. Particles in the substance must collide and have enough energy.  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 7. The factor that would NOT affect the rate of chemical reaction. A. Concentration B. Humidity C. Particle Size D. Temperature  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 8. The factor that will slow down the rate of chemical reaction. A. Manual stirring of the substance. B. Placing substance in a hot water. C. Placing products in iced water. D. Placing reactants in ice bath.  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 9. The factor that does NOT show evidence of chemical reaction. A. Absorption of heat B. Change of color C. Change of size D. Liberation of heat  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 10. The measure of the hotness or coldness of a substance A. Energy B. Humidity C. Temperature D. Thermometer  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 11. The substance formed as a result of a chemical reaction. A. Product B. Reactant C. Resistance D. Substrate  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 12. The measure of how much exposed area a solid object has, expressed in square units. A. Volume B. Surface C. Surface Area D. Concentration  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 13. The substance that is dissolved in a solution. A. Solid B. Solute C. Solvent D. Substance  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 14. The component of a solution that is present in the greatest amount. A. Sample B. Solute C. Solvent D. Substance  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 15. A form of matter that has definite composition and distinct characteristics. A. Atoms B. Compound C. Mixture D. Substance  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 16. The rate at which molecules collide will have impact on the overall reaction rate.. TRUE. FALSE  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 17. What conditions must be met in order for a chemical reaction to occur?. Collision with proper orientation. Sufficient activation energy. Adding more reactant particles. Both collision with proper orientation and sufficient energy  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 18. A collision is considered _________ when it does not result in product formation. Effective. Ineffective. Less Effective. More Effective  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 19. Greater number of reactant molecules are more ______ at higher temperatures.. Concentrated. Heated. Energetic. Active  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 20. The lesser number of reactant molecules the greater probability for effective collisions to form products.. TRUE. FALSE  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 21. What conditions must be met in order for a chemical reaction to occur?. Collision with proper orientation. Sufficient activation energy. Adding more reactant particles. Both collision with proper orientation and sufficient energy  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 22. Which of the following would NOT increase the rate of reaction?. Increasing the temperature. Adding catalyst. Increasing the volume. Increasing the concentrations  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 23. Suppose you dissolve zinc (Zn) in hydrochloric acid (HCl) and add more acid than usual. Then drop pieces of zinc. What factor does NOT affect the rate of the reaction?. Surface area of the Zinc. Concentration of the reactant. Temperature of the solution. Amount of Hydrochloric acid  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 24. Activation energy is the amount of energy required to _________. Break the bonds between the reacting molecules. Make the reacting particles collide. Form the bonds between the product molecules. Convert the reactant to a single product  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 25. Why does a candle burn more rapidly when placed in an open jar than in air? What accounts for this reaction?. Higher Oxygen concentration. Greater surface area of the jar. Increasing the surrounding temperature. Length of the candle  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 26. What will be the effect in collision when there is doubling concentrations?. increases. decreases. reduced to half. none  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 27. This happens when molecules collide with sufficient energy and proper orientation.. Proper collision. Improper collision. Ineffective collision. Effective collision  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 28. When there is high concentration, there is ____ collisions.. few. less. more. none  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 29. This states that for a chemical reaction to occur, reacting particles must collide with one another.. collision theory. chemical reaction. kinetic energy. activation energy  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 30. A collision is considered _________ when it does not result in product formation. effective. ineffective. less effective. more effective  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 31. Greater number of reactant molecules are more ______ at higher temperatures.. concentrated. heated. energetic. more effective  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 32. This is a process of speeding up a reaction by using catalyst.. Catalysis. Inhibition. Reactions. Collisions  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 33. This occurs when a catalyst and the reactants are in the same physical state.. Catalytic process. Heterogeneous catalysis. Enzymatic process. Homogeneous catalysis  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 34. This is known as the catalyst in all living system.. Homogeneous catalyst. Heterogeneous catalyst. Enzymes. Inhibitor  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 35. Which of the following statements best describes the Second Law of Thermodynamics?. The internal energy of the universe is constant.. Energy can be neither created nor destroyed.. For any spontaneous process, the entropy of the universe increases.. At absolute zero, the entropy of a perfect crystal is considered to be zero.  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 36. The thermodynamic quantity that expresses the degree of disorder in a system is __________.. enthalpy. entropy. internal energy. bond energy  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 37. The entropy will decrease when______. a solid changes to a liquid.. a liquid changes to solid.. a molecule is broken into two or more smaller molecules.. a reaction occurs that results in an increase in the number of moles of gas.  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 38. When heat is added to a pure liquid, the temperature. increases and the entropy is unchanged.. increases and the entropy increases.. increases and the entropy decreases.. is unchanged and the entropy increases.  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 39. Predict whether the following processes are spontaneous as described, spontaneous in the reverse direction, or in equilibrium. When a piece of metal heated to 150°C is added to water at 40°C, the water gets hotter.. spontaneous. spontaneous in the reverse direction. equilibrium. None of the above  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 40. Predict whether the following processes are spontaneous as described, spontaneous in the reverse direction, or in equilibrium. Water at room temperature decomposes into hydrogen gas and oxygen gas.. spontaneous. spontaneous in the reverse direction. equilibrium. None of the above Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 41. The element mercury, Hg, is a silvery liquid at room temperature. The normal freezing point of mercury is –38.9 °C, and its molar enthalpy of fusion is ΔHfusion = 2.29 kJ/mol. What is the entropy change of the system when 60.0g of Hg(l) freezes at the normal freezing point? Molar Mass of Hg(l) = 200.59 g/mol A. – 1.22 J/K B. – 2.44 J/K C. – 2.64 J/K D. – 2.92 J/K E. cannot be determined Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 42. Aluminum has a density lower than those of other common metals, at approximately one third that of steel. The normal freezing point of aluminum is 660.3°C, and its molar enthalpy of fusion is ΔHfusion = 8.66 kJ/mol. What is the entropy change of the system when 60.0g of Al(s) freezes at the normal freezing point? Molar mass of Al = 26.98 g/mol A. – 17.2 J/K B. – 19.2 J/K C. – 20.6 J/K D. – 21.6 J/K E. cannot be determined 43. Gold is an excellent conductor of heat and electricity. It is a soft, yellow metal with a beautiful lustrous sheen. It is the most malleable and ductile of all the elements and a single gram can be beaten into a one square meter sheet of gold leaf. The normal freezing point of gold is 1063°C, and its molar enthalpy of fusion is ΔHfusion = 13.2 kJ/mol. What is the entropy change of the system when 60.0g of Au(s) freezes at the normal freezing point? Molar mass of Gold = 197 g/mol A. – 1.51 J/K B. – 2.51 J/K C. – 3.31 J/K D. – 4.31 J/K E. cannot be determined  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 44. It is the movement of the entire molecule from one place to another.. Gravitional. Rotational. Translational. Vibrational  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 45. Periodic motion of atoms within a molecule.. Gravitional. Rotational. Translational. Vibrational  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 46. When heat is added to a system, the amount of heat added can. decrease the temperature, decrease internal energy, and do no external work.. increase the temperature, increase internal energy, and do external work.. increase the temperature, decrease internal energy, and do external work.. decrease the temperature, increase internal energy, and do no external work.  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 47. The second law of thermodynamics tells us that heat cannot flow from. hot to cold ever.. cold to hot ever.. hot to cold without external energy.. cold to hot without external energy.  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 48. Heat engines such as jet engines are more efficient when run at. high temperatures.. constant temperatures.. low temperatures.. a constant rate.  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 49. The direction of natural processes is from states of. higher order to lower order.. lower order to higher order.. disorganization to organization.. disorder to equilibrium.  Choose the letter of the best answer. Write the chosen letter on a separate sheet of paper. 50. As entropy in a system increases, energy in the system. becomes more ordered.. becomes less ordered.. reaches equilibrium.. moves toward destruction. 51. The element mercury, Hg, is a silvery liquid at room temperature. The normal freezing point of mercury is –38.9 °C, and its molar enthalpy of fusion is ΔHfusion = 2.29 kJ/mol. What is the entropy change of the system when 103 g of Hg(l) freezes at the normal freezing point? Molar Mass of Hg(l) = 200.59 g/mol – 5.01 J/K – 5.97 J/K – 6.01 J/K – 6.97 J/K cannot be determined 52.Gold is an excellent conductor of heat and electricity. It is a soft, yellow metal with a beautiful lustrous sheen. It is the most malleable and ductile of all the elements and a single gram can be beaten into a one square meter sheet of gold leaf. The normal freezing point of gold is 1063°C, and its molar enthalpy of fusion is ΔHfusion = 13.2 kJ/mol. What is the entropy change of the system when 155g of Au(s) freezes at the normal freezing point? Molar mass of Gold = 197 g/mol – 7.77 J/K – 8.26 J/K – 8.78 J/K – 9.25 J/K cannot be determined 53.Aluminum has a density lower than those of other common metals, at approximately one third that of steel. The normal freezing point of aluminum is 660.3°C, and its molar enthalpy of fusion is ΔHfusion = 8.66 kJ/mol. What is the entropy change of the system when 85.0g of Al(s) freezes at the normal freezing point? Molar mass of Al = 26.98 g/mol – 29.2 J/K – 29.7 J/K – 32.2 J/K – 32.7 J/K cannot be determined 54.Copper is a reddish metal with a face-centered cubic crystalline structure. It reflects red and orange light and absorbs other frequencies in the visible spectrum, due to its band structure, so it as a nice reddish color. It is malleable, ductile, and an extremely good conductor of both heat and electricity. The normal freezing point of copper is 1085°C, and its molar enthalpy of fusion is ΔHfusion = 13.2 kJ/mol. What is the entropy change of the system when 65.0g of Cu(s) freezes at the normal freezing point? Molar mass of Cu = 63.55 g/mol – 6.88 J/K – 7.88 J/K – 8.94 J/K – 9.94 J/K cannot be determined 55. Aluminum has a density lower than those of other common metals, at approximately one third that of steel. The normal freezing point of aluminum is 660.3°C, and its molar enthalpy of fusion is ΔHfusion = 8.66 kJ/mol. What is the entropy change of the system when 135 g of Al(s) freezes at the normal freezing point? Molar mass of Al = 26.98 g/mol – 36.4 J/K – 36.8 J/K – 46.4 J/K – 46.8 J/K cannot be determined 56.Copper is a reddish metal with a face-centered cubic crystalline structure. It reflects red and orange light and absorbs other frequencies in the visible spectrum, due to its band structure, so it as a nice reddish color. It is malleable, ductile, and an extremely good conductor of both heat and electricity. The normal freezing point of copper is 1085°C, and its molar enthalpy of fusion is ΔHfusion = 13.2 kJ/mol. What is the entropy change of the system when 70.0g of Cu(s) freezes at the normal freezing point? Molar mass of Cu = 63.55 g/mol – 10.2 J/K – 10.7 J/K – 12.2 J/K – 17.7 J/K cannot be determined 57. The element mercury, Hg, is a silvery liquid at room temperature. The normal freezing point of mercury is –38.9 °C, and its molar enthalpy of fusion is ΔHfusion = 2.29 kJ/mol. What is the entropy change of the system when 59.0g of Hg(l) freezes at the normal freezing point? Molar Mass of Hg(l) = 200.59 g/mol – 2.87 J/K – 3.85 J/K – 4.87 J/K – 6.85 J/K cannot be determined 58.Gold is an excellent conductor of heat and electricity. It is a soft, yellow metal with a beautiful lustrous sheen. It is the most malleable and ductile of all the elements and a single gram can be beaten into a one square meter sheet of gold leaf. The normal freezing point of gold is 1063°C, and its molar enthalpy of fusion is ΔHfusion = 13.2 kJ/mol. What is the entropy change of the system when 35.0 g of Au(s) freezes at the normal freezing point? Molar mass of Gold = 197 g/mol – 1.76 J/K – 2.26 J/K – 3.76 J/K – 4.26 J/K cannot be determined 59. Aluminum has a density lower than those of other common metals, at approximately one third that of steel. The normal freezing point of aluminum is 660.3°C, and its molar enthalpy of fusion is ΔHfusion = 8.66 kJ/mol. What is the entropy change of the system when 89.0 g of Al(s) freezes at the normal freezing point? Molar mass of Al = 26.98 g/mol – 30.6 J/K – 31.6 J/K – 34.0 J/K – 35.0 J/K cannot be determined 60. Copper is a reddish metal with a face-centered cubic crystalline structure. It reflects red and orange light and absorbs other frequencies in the visible spectrum, due to its band structure, so it as a nice reddish color. It is malleable, ductile, and an extremely good conductor of both heat and electricity. The normal freezing point of copper is 1085°C, and its molar enthalpy of fusion is ΔHfusion = 13.2 kJ/mol. What is the entropy change of the system when 105 g of Cu(s) freezes at the normal freezing point? Molar mass of Cu = 63.55 g/mol – 15.1 J/K – 16.1 J/K – 17.1 J/K – 19.1 J/K cannot be determined