CST Practice Test Young NAME CST Practice Test Multiple Choice Questions 1) At 1 atm and 298 K, which of the K a values listed below represents the strongest acid? 5) Which electron-dot symbol represents an atom of chlorine in the ground state? (a) 1.1 10 7 1.8 10 5 (c) 5.6 10 11 (d) 4.6 10 4 (a) (c) 2) Given the system at equilibrium: PbCO 3 (s) Pb 2+ (aq) + CO 3 2 (aq) (d) How will the addition of Na 2 CO 3 (aq) affect [Pb 2+ ](aq) and the mass of PbCO 3 (s)? (a) [Pb 2+ ](aq) will decrease and the mass of PbCO 3 (s) will decrease. [Pb 2+ ](aq) will decrease and the mass of PbCO 3 (s) will increase. (c) [Pb 2+ ](aq) will increase and the mass of PbCO 3 (s) will decrease. (d) [Pb 2+ ](aq) will increase and the mass of PbCO 3 (s) will increase. 3) When a catalyst is added to a system at equilibrium, a decrease occurs in (a) the heat of the reaction activation energy (c) potential energy of the reactants (d) potential energy of the products 6) Which statement describes the elements in Period 3? (a) Each successive element has a greater atomic radius. Each successive element has a lower electronegativity. (c) All elements have similar chemical properties. (d) All elements have valence electrons in the same principal energy level. 7) What volume will a 300.-milliliter sample of a gas at STP occupy when the pressure is doubled at constant temperature? (a) 150. ml 450. ml (c) 300. ml (d) 600. ml 8) Which type of bond is formed when an atom of potassium transfers an electron to a bromine atom? 4) Given the reaction at equilibrium: X + Y 2Z + heat The concentration of the product could be increased by (a) adding a catalyst adding more heat to the system (c) increasing the concentration of Y (d) decreasing the concentration of X (a) metallic ionic (c) nonpolar covalent (d) polar covalent
9) C 3 H 8 + 5O 2 3CO 2 + 4H 2 O Which of these could be added to the above reaction to increase the rate of reaction over time? (a) C 3 H 8 and O 2 C 3 H 8 and CO 2 (c) O 2 and CO 2 (d) O 2 and H 2 O 14) A student observed that when sodium hydroxide was dissolved in water, the temperature of the water increased. The student should conclude that the dissolving of sodium hydroxide (a) is endothermic is exothermic (c) produces an acid solution (d) produces a salt solution 10) The heat energy required to change a unit mass of a solid into a liquid at constant temperature is called (a) heat of vaporization heat of formation (c) heat of solution (d) heat of fusion 15) Given the nuclear equation: What is particle X? 14 7 N + X 16 8 O + 2 1 H 11) Given the reaction at equilibrium: (a) an alpha particle a beta particle (c) a deuteron (d) a triton 2A(g) + 3B(g) A 2 B 3 (g) + heat Which change will not affect the equilibrium concentrations of A(g), B(g), and A 2 B 3 (g)? (a) adding more A(g) adding a catalyst (c) increasing the temperature (d) increasing the pressure 16) Given the reaction: N 2 (g) + 3H 2 (g) 2NH 3 (g) + energy If the temperature is increased and the pressure is kept constant, the new equilibrium concentration will be (a) less for NH 3 (g) the same for NH 3 (g) (c) less for N 2 (g) (d) the same for N 2 (g) 12) What occurs when a substance melts? (a) It changes from solid to liquid, and heat is absorbed. It changes from solid to liquid, and heat is released. (c) It changes from liquid to solid, and heat is absorbed. (d) It changes from liquid to solid, and heat is released. 17) In a mixture of water, sugar, and salt, which ingredient(s), if any, are solvents? (a) Water only Water and sugar only (c) Sugar and salt only (d) Water, sugar, and salt 18) Which property do most acids share? 13) Which phase change is exothermic? (a) solid to liquid (c) liquid to solid solid to gas (d) liquid to gas (a) Bitter taste Sour taste (c) Slippery feel (d) Faint color
19) Given the reaction: 2N 2 (g) + O 2 (g) 2N 2 O(g) Which statement is true when this closed system reaches equilibrium? (a) All of the N 2 (g) has been consumed. All of the O 2 (g) has been consumed. (c) Pressure changes no longer occur. (d) The forward reaction no longer occurs. 25) In a reversible chemical reaction, which factors must be equal when the reaction is at equilibrium? (a) rate at which reactants are formed and rate at which products are formed concentration of reactants and concentration of products (c) potential energy of reactants and potential energy of products (d) activation energy of reactants and activation energy of products 20) Which type of bond exists between an atom of carbon and an atom of fluorine? (a) ionic metallic (c) polar covalent (d) nonpolar covalent 21) Which of these is the best conductor of electricity? (a) Distilled water Salt water (c) Carbonated water (d) Sugar water 22) The ability of H 2 SO 4 (aq) to change blue litmus red is mainly due to the presence of 26) In a reversible reaction, chemical equilibrium is attained when the (a) rate of the forward reaction is greater than the rate of the reverse reaction rate of the reverse reaction is greater than the rate of the forward reaction (c) concentration of the reactants reaches zero (d) concentration of the products remains constant 27) What are the characteristics of a neutron? (a) It has no charge and no mass. It has no charge and a mass of 1 amu. (c) It has a charge of +1 and no mass. (d) It has a charge of +1 and a mass of 1 amu. (a) SO 2 molecules H 2 O molecules (c) H 3 O + (aq) ions (d) SO 4 2 (aq) ions 28) Given the solution at equilibrium: PbI 2 (s) Pb 2+ (aq) + 2I (aq) 23) If equal volumes of 0.1 M NaOH and 0.1 M HCl are mixed, the resulting solution will contain a salt and The addition of which nitrate salt will cause a decrease in the concentration of I (aq)? (a) HCl NaOH (c) H 2 O (d) NaCl (a) Pb(NO 3 ) 2 (c) LiNO 3 Ca(NO 3 ) 2 (d) KNO 3 24) Carbon dioxide gas is most soluble in water under conditions of (a) high pressure and low temperature high pressure and high temperature (c) low pressure and low temperature (d) low pressure and high temperature 29) Which properties are most common in nonmetals? (a) low ionization energy and low electronegativity low ionization energy and high electronegativity (c) high ionization energy and low electronegativity (d) high ionization energy and high electronegativity
30) Which ion has the largest radius? (a) Na + (c) K + Mg 2+ (d) Ca 2+ 31) The forces between atoms that create chemical bonds are the result of interactions between (a) nuclei electrons (c) protons and electrons (d) protons and nuclei 34) What happens when NaCl(s) is dissolved in water? (a) Cl ions are attracted to the oxygen atoms of water molecules. Na + ions are attracted to the oxygen atoms of water molecules. (c) Cl ions are repelled by the hydrogen atoms of water molecules. (d) Na + ions are repelled by the oxygen atoms of water molecules. 35) Which pair of atoms is held together by a covalent bond? 32) The graph below represents the uniform cooling of a substance, starting with the substance as a gas above its boiling point. (a) HCl LiCl (c) NaCl (d) KCl 36) A condensation polymerization reaction is best described as the (a) joining of monomers by the removal of oxygen joining of monomers by the removal of water (c) oxidation of a hydrocarbon by oxygen (d) oxidation of a hydrocarbon by water 37) As the number of neutrons in the nucleus of a given atom of an element increases, the atomic number of that element During which interval is the substance completely in the liquid phase? (a) decreases increases (c) remains the same (a) AB BC (c) CD (d) DE 38) Experiments performed to reveal the structure of atoms led scientists to conclude that an atom s 33) The energy absorbed when ammonium chloride dissolves in water can be measured in (a) degrees kilocalories (c) moles per liter (d) liters per mole (a) positive charge is evenly distributed throughout its volume negative charge is mainly concentrated in its nucleus (c) mass is evenly distributed throughout its volume (d) volume is mainly unoccupied 39) The nucleus of which atom contains 48 neutrons? (a) 32 16 S (c) 85 37 Rb 48 22 Ti (d) 112 48 Cd
40) When an atom loses an electron, the atom becomes an ion that is (a) positively charged and gains a small amount of mass positively charged and loses a small amount of mass (c) negatively charged and gains a small amount of mass (d) negatively charged and loses a small amount of mass 42) The atomic mass unit is defined as exactly 1 12 the mass of an atom of (a) 12 6 C (c) 24 12 Mg 14 6 C (d) 26 12 Mg 43) Which type of radiation continues in a straight line when passed through an electric field? 41) Which shows the correct Lewis structure for H 2 O? (a) H O H (a) alpha beta (c) gamma (d) proton H O H 44) Which atom in the ground state has five electrons in its outer level and ten electrons in its kernel? (a) C Cl (c) Si (d) P (c) H O H (d) H O H 45) Which list of substances is in order of increasing intermolecular forces? (a) Ice, soda, honey, helium Soda, ice, honey, helium (c) Helium, soda, honey, ice (d) Helium, soda, ice, honey For question 46
46) The forward reaction is best described as an (a) exothermic reaction in which energy is released exothermic reaction in which energy is absorbed (c) endothermic reaction in which energy is released (d) endothermic reaction in which energy is absorbed 52) Which of these has base units made up of amino acids? (a) Protein Phospholipids (c) Sucrose (d) DNA 47) As HCl(g) is added to water, the ph of the water solution (a) decreases increases (c) remains the same 53) Which of these combine together to form proteins? (a) Amino acids Lipids (c) Sugars (d) Nucleic acids 48) Which list is in order of increasing penetrating strength? (a) Alpha, gamma, beta Alpha, beta, gamma (c) Gamma, alpha, beta (d) Gamma, beta, alpha 54) Which element in Group 1 has the greatest tendency to lose an electron? (a) cesium rubidium (c) potassium (d) sodium 49) An increase in the temperature of a system at equilibrium favors the 55) The diagram below represents radiation passing through an electric field. (a) endothermic reaction and decreases its rate endothermic reaction and increases its rate (c) exothermic reaction and decreases its rate (d) exothermic reaction and increases its rate 50) How are protons held together in the nucleus of an atom? (a) Nuclear forces Electromagnetic attraction (c) Electromagnetic repulsion (d) Rotational inertia The arrow labeled A most likely represents (a) a positron (c) alpha radiation an electron (d) gamma radiation 51) What is the concentration of a solution of 10. moles of copper (II) nitrate in 5.0 liters of solution? (a) 0.50 M (c) 5.0M 2.0 M (d) 10. M 56) What is the total number of valence electrons in an atom of xenon? (a) 0 (c) 8 2 (d) 18
57) The bond between hydrogen and oxygen in a water molecule is classified as (a) ionic and nonpolar ionic and polar (c) covalent and nonpolar (d) covalent and polar 62) In the equation 234 90 X represents (a) Th 234 91 0 +1 e (c) 1 0 n 0 1 e (d) 1 1 H Pa + X the symbol 58) When ionic bonds are formed, metallic atoms tend to (a) lose electrons and become negative ions lose electrons and become positive ions (c) gain electrons and become negative ions (d) gain electrons and become positive ions 63) A gas sample has a volume of 25.0 milliliters at a pressure of 1.00 atmosphere. If the volume increases to 50.0 milliliters and the temperature remains constant, the new pressure will be (a) 1.00 atm 2.00 atm (c) 0.250 atm (d) 0.500 atm 59) Which phase change is exothermic? (a) H 2 O(s) H 2 O(l) H 2 O(l) H 2 O(s) (c) H 2 O(s) H 2 O(g) (d) H 2 O(l) H 2 O(g) 64) Which noble gas has the highest first ionization energy? (a) radon krypton (c) neon (d) helium 60) Given the reaction: A 2 (g) + B 2 (g) 2AB(g) + heat An increase in the concentration of A 2 (g) will (a) decrease the production of AB(g) decrease the frequency of collisions between A 2 (g) and B 2 (g) (c) increase the production of B 2 (g) (d) increase the frequency of collisions between A 2 (g) and B 2 (g) 61) Which subatomic particle is found in the nucleus of all isotopes of hydrogen? (a) proton neutron (c) electron (d) positron 65) Which statement explains why fusion reactions are difficult to initiate? (a) Positive nuclei attract each other. Positive nuclei repel each other. (c) Neutrons prevent nuclei from getting close enough to fuse. (d) Electrons prevent nuclei from getting close enough to fuse. 66) Given the reaction: Cl(g) + Cl(g) Cl 2 (g) + energy Which statement best describes the reaction? (a) A bond is formed and energy is absorbed. A bond is formed and energy is released. (c) A bond is broken and energy is absorbed. (d) A bond is broken and energy is released.
67) The reaction during which monomers are combined and water is released is called (a) saponification neutralization (c) addition polymerization (d) condensation polymerization 73) Hotter temperatures generally make less soluble in water. (a) gases solids (c) liquids (d) salts 68) A catalyst will affect the rate of the forward reaction by changing the (a) activation energy heat of reaction (c) heat of formation (d) potential energy of the products 69) What is the correct formula for magnesium fluoride? (a) MgF Mg 2 F (c) Mg 2 F 2 (d) MgF 2 74) Why does a spoonful of loose salt crystals dissolve faster in water than does a block of the same amount of salt? (a) The loose salt crystals require less energy to dissolve than the block of salt. The loose salt crystals have more surface area exposed to the water than the block of salt. (c) The loose salt crystals are less soluble than the block of salt. (d) The loose salt crystals have fewer chemical bonds to break than the block of salt. 75) Which two elements have chemical properties that are most similar? 70) If M represents an alkali metal, what is the formula for the compound formed by M and oxygen? (a) Cl and Ar Li and Na (c) K and Ca (d) C and N (a) MO 2 (c) M 2 O 3 M 2 O (d) M 3 O 2 76) 71) Which formula correctly represents antimony (V) oxide? (a) SbO 5 (c) Sb 2 O 5 Sb 5 O (d) Sb 5 O 2 72) Which acid-base pair will always undergo a reaction that produces a neutral solution? (a) a weak acid and a weak base a weak acid and a strong base (c) a strong acid and a weak base (d) a strong acid and a strong base Carbonated beverages are bottled and canned under pressure, because pressure greatly (a) decreases the solubility of solids in liquids. increases the solubility of solids in liquids. (c) decreases the solubility of gases in liquids. (d) increases the solubility of gases in liquids.
77) How does the temperature of water influence the solubility of different substances? (a) Hotter water generally makes solids more soluble. Colder water generally makes liquids more soluble. (c) Hotter water generally makes gases more soluble. (d) Water temperature does not affect the solubility of substances. 82) Adding a catalyst to a chemical reaction changes the rate of reaction by causing (a) a decrease in the activation energy an increase in the activation energy (c) a decrease in the heat of reaction (d) an increase in the heat of reaction 78) When HCl is dissolved in water, the only positive ion present in the solution is the (a) hydrogen ion hydroxide ion (c) hydride ion (d) chloride ion 83) In which pair of elements do the nuclei of the atoms contain the same number of neutrons? (a) 7 3 Li and 9 4 Be (c) 23 11 14 7 N and 16 8 O (d) 32 16 Na and 24 12 Mg S and 35 17 Cl 79) Given the solution at equilibrium: CaSO 4 (s) Ca 2+ (aq) + SO 4 2 (aq) When Na 2 SO 4 is added to the system, how will the equilibrium shift? (a) The amount of CaSO 4 (s) will decrease, and the concentration of Ca 2+ (aq) will decrease. The amount of CaSO 4 (s) will decrease, and the concentration of Ca 2+ (aq) will increase. (c) The amount of CaSO 4 (s) will increase, and the concentration of Ca 2+ (aq) will decrease. (d) The amount of CaSO 4 (s) will increase, and the concentration of Ca 2+ (aq) will increase. 84) The properties of carbon are expected to be most similar to those of (a) boron aluminum (c) silicon (d) phosphorus 85) Which type of radiation is most similar to high-energy x rays? (a) alpha beta (c) neutron (d) gamma 80) Given the nuclear reaction: 9 4 Be + X 12 6 C + 1 0 n What is the identity of particle X? (a) alpha particle beta particle (c) proton (d) neutron 86) When an acid is dissolved in water, it will (a) release H + ions into the water. release H ions into the water. (c) release OH ions into the water. (d) not release ions into the water. 87) Which atom will form an ionic bond with a Br atom? 81) In which list can all particles be accelerated by an electric field? (a) N Li (c) O (d) C (a) alpha particles, beta particles, and neutrons alpha particles, beta particles, and protons (c) alpha particles, protons, and neutrons (d) beta particles, protons, and neutrons 88) What is the ph of a solution that results from the complete neutralization of an HCl solution with a KOH solution? (a) 1 (c) 10 7 (d) 4
89) Which atoms are isotopes of the same element? 94) Which change of phase is exothermic? (a) 24 12 20 10 25 X and 12 X (c) 31 15 20 X and 11 X (d) 31 19 X and 32 16 X X and 31 19 X (a) solid to liquid gas to liquid (c) solid to gas (d) liquid to gas 95) Proteins are produced through the process of 90) Which subatomic particles have a mass of approximately 1 atomic mass unit each? (a) addition substitution (c) polymerization (d) combustion (a) proton and electron proton and neutron (c) neutron and positron (d) electron and positron 91) Given the reaction at equilibrium: A(g) + B(g) C(g) + D(g) 96) The mass of a calcium atom is due primarily to the mass of its (a) protons, only neutrons, only (c) protons and neutrons (d) protons and electrons The addition of a catalyst will (a) shift the equilibrium to the right shift the equilibrium to the left (c) increase the rate of forward and reverse reactions equally (d) have no effect on the forward or reverse reactions 92) Given the reaction at equilibrium: BaCrO 4 (s) Ba 2+ (aq) + CrO 2 4 (aq) Which substance, when added to the mixture, will cause an increase in the amount of BaCrO 4 (s)? 97) Which statement about the mass of an electron is correct? (a) The mass of an electron is equal to the mass of a proton. The mass of an electron is less than the mass of a proton. (c) The mass of an electron is equal to the mass of a neutron. (d) The mass of an electron is greater than the mass of a neutron. (a) K 2 CO 3 (c) BaCl 2 CaCO 3 (d) CaCl 2 93) Given the reaction: 2SO 2 (g) + O 2 (g) 2SO 3 (g) The value of the equilibrium constant (K eq ) will be changed by increasing the (a) pressure temperature (c) concentration of SO 2 (g) (d) concentration of SO 3 (g)
98) A potential energy diagram of a chemical reaction is shown below. 102) What is the molarity of a solution that contains 40. grams of NaOH in 0.50 liter of solution? (a) 1.0 M 2.0 M (c) 0.50 M (d) 0.25 M 103) Which graph best shows the relationship between Kelvin temperature and average kinetic energy? What is the difference between the potential energy of the reactants and the potential energy of the products? (a) (c) (a) 20 kcal 40 kcal (c) 60 kcal (d) 80 kcal (d) 99) What is the atomic number of an element that has six protons and eight neutrons? (a) 6 (c) 8 2 (d) 14 100) Given the reaction: 226 88 Ra 222 86 Rn + X Which type of emanation is represented by X? (a) alpha particle beta particle 101) Given the system at equilibrium: (c) proton (d) positron H 2 (g) + F 2 (g) 2HF(g) + heat 104) When alpha particles are used to bombard gold foil, most of the alpha particles pass through undeflected. This result indicates that most of the volume of a gold atom consists of (a) neutrons protons 105) Atoms of metals tend to (c) deuterons (d) unoccupied space (a) lose electrons and form negative ions lose electrons and form positive ions (c) gain electrons and form negative ions (d) gain electrons and form positive ions Which change will not shift the point of equilibrium? (a) changing the pressure changing the temperature (c) changing the concentration of H 2 (g) (d) changing the concentration of HF(g) 106) Which of the following 0.1 M solutions has the lowest ph? (a) 0.1 M NaOH 0.1 M CH 3 OH (c) 0.1 M NaCl (d) 0.1 M HCl
107) Which of the following elements has the strongest attraction for electrons? (a) boron aluminum (c) oxygen (d) sulfur 108) Which particles may be gained, lost, or shared by an atom when it forms a chemical bond? (a) protons electrons (c) neutrons (d) nucleons 109) The potential energy diagram of a chemical reaction is shown below. 110) Given the reaction at equilibrium: N 2 (g) + 3H 2 (g) 2NH 3 (g) + 22 kcal Which stress would cause the equilibrium to shift to the left? (a) increasing the temperature increasing the pressure (c) adding N 2 (g) to the system (d) adding H 2 (g) to the system 111) What is the total number of valence electrons in an atom of boron in the ground state? (a) 1 (c) 3 7 (d) 5 112) What is the total number of protons and neutrons in 86 an atom of 37 Rb? (a) 37 (c) 86 49 (d) 123 113) Which type of radiation has zero mass and zero charge? Which arrow represents the part of the reaction most likely to be affected by the addition of a catalyst? (a) A B (c) C (d) D (a) alpha beta (c) neutron (d) gamma 114) The elements known as the alkaline earth metals are found in Group (a) 1 (c) 16 2 (d) 17
CST Practice Test Young Answer Key Multiple Choice Questions 1) d 2) b 3) b 4) c 5) d 6) d 7) a 8) b 9) a 10) d 11) b 12) a 13) c 14) b 15) a 16) a 17) a 18) b 19) c 20) c 21) b 22) c 23) c 24) a 25) a 26) d 27) b 28) a 29) d 30) c 31) c 32) c 33) b 34) b 35) a 36) b 37) c 38) d 39) c 40) b 41) d 42) a 43) c 44) d 45) c 46) d 47) a 48) b 49) b
50) a 51) b 52) a 53) a 54) a 55) b 56) c 57) d 58) b 59) b 60) d 61) a 62) b 63) d 64) d 65) b 66) b 67) d 68) a 69) d 70) b 71) c 72) d 73) a 74) b 75) b 76) d 77) a 78) a 79) c 80) a 81) b 82) a 83) c 84) c 85) d 86) a 87) b 88) b 89) a 90) b 91) c 92) c 93) b 94) b 95) c 96) c 97) b 98) a 99) a 100) a 101) a 102) b 103) a 104) d 105) b 106) d 107) c 108) b 109) b
110) a 111) c 112) c 113) d 114) b