According to the law of the conservation of atoms, the total mass of the reacting substances is

1. MATTER, ENERGY AND CHANGE According to the law of the conservation of atoms, the total mass of the reacting substances is a) always greater than the total mass of the products b) always less than the total mass of the products c) sometimes greater than the total mass of the products d) always equal to the total mass of the products Chemical equations : a) describe chemical reactions b) show how to write chemical formulas c) give directions for naming chemical compounds d) describe only biological changes Which of the following is a chemical property? a) color b) density c) freezing point d) reactivity with oxygen Chemistry is chiefly concerned with the study of which of the following types of changes in substances? a) changes in composition b) changes in shape c) changes in volume d) changes in mass If 14 atoms of carbon react with 28 atoms of oxygen to form the product carbon dioxide, how many atoms are contained in the carbon dioxide that is produced? a) 14 b) 21 c) 28 d) 42

2. SCIENTIFIC MEASUREMENT Which of the following measurements contains 2 significant figures? a) .0040cm b) 403m c) 92.00L d) 6.01g A temperature reading of -4.0oC corresponds to a Kelvin reading of a) 297.6 K b) 238 K c) 269 K d) 271 K Which of the following metric prefixes means 1000 times larger? a) kilo b) milli c) deka d) mega Express the following measurement in scientific notation, 0.005202g a) 5.20 x 102g b) 52.02 x 10-4g c) 5.202 x 10-3g d) 5.2 x 10-3g Express the product of 4.00 x 10-2 m X 8.1 x 102 m using the correct number of significant digits. a) 3 x 101 b) 3.24 x 101 c) 3.0 x 101 d) 3.3 x 101 e) 3.2 x 101

3. A conversion factor ____. a) both equal the value of 1 b) is a ratio of equivalent measurements c) has the same units d) all of the above How would the heat flow of 16.0 cal/sec be expressed in joules per hour? a) 241 J/hr b) 241 000 J/hr c) 2410 J/hr d) 2 410 000 J/hr e) 24 100 J/hr How many significant figures are in the measurement 0.0235 grams? a) 5 b) 4 c) 3 d) 2 What is the density of 3.0 grams of a substance with a volume of 2.0 mL? a) 1.5 g b) 1.5 g/cm3 c) 1.5 cm3 d) .66 g/cm3 In order to find the specific heat of a substance, what information is required? a) mass and amount of heat absorbed b) amount of matter and temperature change c) mass, change in temp. and heat absorbed d) mass, density and final temperature

4. ATOMIC STRUCTURE The nucleus of an atom: a) is composed of protons and neutrons b) is composed of protons and electrons c) occupies a large volume of the atom d) has no charge What is the smallest particle of an element that retains the properties of the element? a) an atom b) a molecule c) a proton d) an electron The sum of the protons and neutrons in an atom equals the: a) atomic number b) nucleus number c) mass number d) atomic mass Hydrogen-3 has ____protons, ____neutrons, and _____electrons. a) 1,0,1 b) 1,1,1 c) 3,0,1 d) 1,2,1 Isotopes of the same element have different ____ . a) numbers of neutrons b) numbers of protons c) numbers of electrons d) atomic numbers The quantum mechanical model of the atom____ a) defines the exact path of an electron around the nucleus b) was proposed by Niels Bohr c) has many analogies in the visible world d) is concerned with the probability of finding an electron

5. ELECTRONS AND CONFIGURATIONS The electron configuration of potassium is____ a) 1s2 2s2 2p6 3s2 3p6 4s1 b) 1s2 2s2 2p10 3s2 3p3 c) 1s2 2s2 3s2 3p6 3d1 d) 1s2 2s2 2p6 3s2 3p6 Electrons in an atom not at their lowest possible energy are in the ____ a) excited state b) ground state c) inert state d) quantum state How many energy subshells are there in the 2nd principle energy level? a) 1 b) 2 c) 4 d) 16 If three electrons are available to fill three empty 2p atomic orbitals, how will the electrons be distributed in the three orbitals? a) two electrons in one orbital, one in another, none in the third b) three in one orbital, none in the other two c) one electron in each orbital What types of atomic orbitals are in the third energy level? a) s and p only b) p and d only c) s,p, and d only d) s,p,d, and f

6. *Which two elements are isotopes of one another? *How many neutrons are in element “Y”? *How many electrons are contained in element “Z”? *How many protons does element “X” have?

7. CHEMICAL PERIODICITY The modern periodic table is arranged in order of increasing atomic_____ a) mass b) charge c) number d) radius Elements that have similar chemical properties, a) have nearly the same atomic mass b) have the same number of valence electrons c) have the same number of electrons d) have the same number of protons The energy required to remove one electron from an atom is called, a) excitation energy b) ionization energy c) polarization energy d) electronegativity Which element would have the highest electronegativity? a) H b) He c) Na d) C e) F What is the chief characteristic of noble gases? a) red color b) high density c) high boiling point d) very low reactivity

8. Chemical Bonding When Magnesium atom loses it valence electrons, the charge of the resulting ion is__, a. 2+ b. 2- c. 3+ d. 1+ Which element when combined with fluorine would most likely form an ionic compound? a. lithium b. carbon c. silicon d. chlorine Which element when combined with fluorine would most likely form an ionic compound? a. lithium b. carbon c. silicon d. chlorine In forming chemical bonds, atoms attain: a. a state of lower energy b. a noble gas electron configuration c. greater stability d. all of these Which of these elements does not exist as a diatomic molecules? a. Br b. F c. Ar d. I Which one of the following compounds is not covalent? a. BrCl b. LiCl c. N2O5 d. S2Cl2

9. A double covalent bond consists of: a. two shared electrons b. two pairs of shared electrons c. six shared electrons d. unshared electrons The shape of the carbon tetrachloride (CCl4) molecule is called,__ a. tetrahedral b. planar c. linear d. bent The name of the compound with the formula PO4 is, a. phosphorus oxide b. phosphate c. phosphorus tetraoxide d. phosphite

10. CHEMICAL QUANTITIES How many moles of SO3 are in 2.4 x 1024 molecules of SO3? a) 0.25 b) 3.4 x 1022 c) 4.0 d) 2.9 x 10-23 What is the volume, at STP, of 2.50 moles of carbon monoxide? a) 70 L b) 3.1 L c) 56 L d) 9.0 L The empirical formula of a compound is CH2F. The molar mass of this compound is 66.0 g. The molecular formula of the compound is, a) C4H8F4 b) C4H4F4 c) C2H4F2 d)CH2F What is the molar mass of chromic sulfate, Cr2(SO4)3? a) 148.1 g b) 288.0 g c) 344.2 g d) 392.2 g Which formula is an empirical formula? a) K2O b) H2O2 c) C2H6 d) C6H6 What is the mass of 2.4 moles of water? a) 55.6 grams b) 43.2 grams c) 32.0 grams d) .133 gr

11. CHEMICAL REACTIONS In every balanced equation, each side has the same number of: a) atoms b) moles c) molecules d) coefficients If a combination reaction took place between potassium and chlorine, what is the product? a) KCl b) KCl2 c) PCl d) P2Cl In a complete combustion reaction: a) hydrogen and water are produced b) energy is only absorbed c) oxygen is the major product d) water and carbon dioxide are produced The symbol ↑ in a chemical equation means: a) heat is supplied b) yields c) a precipitate d) gas is formed When the equation Fe + Cl2 -----> FeCl3 is balanced, the coefficient for Cl2 is, a) 1 b) 2 c) 3 d) 4 In order for the reaction 2Al + 6HCl ----> 2AlCl3 + 3H2 to occur, which of the following must be true. a) Al must be above Cl on the activity series b) heat must be supplied c) a gas must be formed d) Al must be above H on the activity series

12. Single Replacement b) Double Replacement • Combustion d) Combination • e) Decomposition   NH4HS ---------> NH3 + H2S C3H8 + 5O2 -----> 3CO2 + 4H2O 3Mg + 2FeCl2 ------> 3MgCl2 + 2Fe S + Cl2 --------> SCl2 NaCl + AgNO3 -----> NaNO3 + AgCl Zn + CuSO4 -----> ZnSO4 + Cu MnSO4 ------> MnO + SO3

13. *Which picture above best illustrates a compound? *Which picture above best illustrates a diatomic molecule? *Which best illustrates a mixture?

14. STOICHIOMETRY Which of the following in an incorrect interpretation of this balanced equation? 2S + 3O2 -----> 2SO3 a) 2 atoms S + 3 molecules O2 ---> 2 molecules SO3 b) 2 grams S + 3 grams O2 -----> 2 grams SO3 c) 2 moles S + 3 moles O2 ------> 2 moles SO3 d) none of the above 3Cu + 8HNO3 (aq)------> 3Cu(NO3)2 + 2NO + 4H2O If you could drop 12 atoms of copper into a beaker containing nitric acid, how many molecules of NO would be produced? a) 2 b) 4 c) 8 d) 12 Calculate the number of moles of water produced when 6.6 moles of Cu(NO3)2 are formed in the reaction. a) 4 mol b) 6.6 mol c) 4.9 mol d) 8.8 mol

15. *A particular reaction is expected to produce 2.6 liters of oxygen gas. In reality, the reaction only produces 1.9 liters of oxygen gas. The percent yield of the reaction is: a) 27% b) 42% c) 73% d) 137% *Stoichiometry problems may involve all of the following except: a) converting among moles, particles, mass and volume b) determining the relationships between reactants and products c) studying the quantitative relationships in chemical formulas d) predicting how fast a reaction will occur *Use the following chemical reaction to answer the following question: 2C6H6 + 7O2 -----> 4CO2 + 6H2O *What volume of CO2 will be produced when 128.0 g of C6H6 reacts at STP?

16. GASES *Standard conditions when working with gases are defined as: a) 0 K and 1 atm b) 0 K and 1mmHg c) 0oC and 1 atm d) 0oC and 1mmHg *The statement defining the relationship between the pressure and volume of a gas at constant temperature is known as: a) Boyle’s Law b) Dalton’s Law c) Charles’ Law d) Gay-Lussac’s Law *A breathing mixture used by scuba divers contains helium, oxygen, and carbon dioxide. What is the partial pressure of oxygen at 1 atm if PHe = 609.6 mmHg and PCO2 = 0.5 mm Hg? *A gas occupies a volume of 0.2 L at 76 mmHg. What will be the new volume at 760mmHg? a) 38L b) 20L c) 2L d) 0.02L *The direct change of a substance from a solid to a gas is called,___ a) evaporation b) sublimation c) condensation d) boiling

17. *Which of these changes would not cause an increase in the pressure of a gaseous system? a) the container is made larger b) additional amounts of the same gas are added to the container c) the temperature is increased d) another gas is added to the container *The high surface tension of water is due to the: a) small size of water molecules b) high kinetic energy of water molecules c) hydrogen bonding between water molecules d) covalent bonds in water molecules • In the statement "like dissolves like," the word "like" refers to similarity in • molecular,_ • a) mass b) size c) energy d) polarity solution is which water is the solvent is described as,___ a) a tincture b) aqueous c) soluble d) saturated

18. *An unknown substance does not dissolve in water but does in benzene. Which of the following statements explains this? a) the substance is polar and benzene is nonpolar b) both the substance and the benzene are polar c) the substance is nonpolar and benzene is polar d) both the substance and benzene are nonpolar *What is the effect of a surfactant on surface tension? a) it increases surface tension b) it decreases surface tension c) it has no effect on surface tension *A small crystal of ammonium chloride is added to a solution of ammonium chloride and water. If the crystal dissolves, the original solution was,___ a) concentrated b) saturated c) unsaturated d) supersaturated *Increasing the temperature of a solution will generally: a) increase the rate at which a solute dissolves b) increase the amount of solute which dissolves c) both a and b d) neither a nor b

19. *If the hydrogen ion concentration is 1 x 10-10 M, what is the pH of the solution? a) 1 b) 4 c) 7 d) 10 e) 14 *In a neutral solution, the [H+] is: a) 10-14 b) zero c) 1 x 107M d) equal to [OH-] *A neutralization reaction can be classified as a: a) combination reaction b) single replacement reaction c) decomposition reaction d) double replacement reaction *An acid and a base react in aqueous solution to produce salt and_______. a) ions b) water c) CO2 gas d) H2 gas *If the pOH of a solution is 10.0, what is the pH of the solution? a) 10.0 b) 4.0 c) 7.0 d) 14.0