SI Chem 177 ACS Practice TestAcids & Bases:ThermochemistrySI Chem 177 ACS Practice Test Acids & Bases:1. All are examples of Lewis acid–base reactions except(A) Cu2+(aq) + 4NH3(aq)  [Cu(NH3)4]2+(aq)(B) HCl(g) + NH3(g)  NH4Cl(s)(C) H+(aq) + OH–(aq)  H2O(l)(D) 2Na(s) + Cl2(g)  2NaCl(s)2. According to the Lewis definition, an acid is a species(A) having a hydrogen ion. (B) donating a pair of electrons.(C) accepting a pair of electrons. (D) accepting a hydrogen ion.3. All are potential Lewis bases except(A) NH3(B) H2O (C) CH4(D) CN–4. Which hydrated metal ion is most acidic under conditions of equal molar concentration in water?(A) Al3+(B) Ba2+(C) K+(D) Zn2+(E) Ag+5. Which element in Group 5A forms the most basic oxide?(A) N (B) P (C) As (D) Sb (E) BiAtomic Structure:6. In what respect does an atom of magnesium differ from a magnesium ion (Mg2+)?(A)The ion has a more stable electronic arrangement than the atom.(B)The positive charge on the nucleus of the ion is two units greater than the nuclear charge on the atom.(C)The ion has two more protons than the atom.(D)The ion will react more readily with free Cl2.(E)The ion has two more planetary electrons than the atom.7. A certain atom has the symbol Px. What does this symbol tell about an atom of the element?(A) It has 148 electrons. (B) It has a valence of 4.(C) It has 221 protons in the nucleus. (D) It has 75 neutrons in the nucleus.(E) Its atomic mass is 73 u.8. The atomic mass of an element is 32.07 u and its atomic number is 16. The number of protons contained in the nucleus of an atom of this element is(A) 16 (B) 31 (C) 32 (D) 489. The atomic mass of an element is 32.07 u and its atomic number is 16. The element forms a simple ion. The ion will most likely have a charge of(A) 1– (B) 2– (C) 3+ (D) 1+110. The nucleus of which atom contains seven neutrons?Atom A n = 1 n = 2 n = 3M = 24, Z = 12 2 e 8 e 2 e Atom B n = 1 n = 2 n = 3M = 15, Z = 7 2 e 5 e Atom C n = 1 n = 2 n = 3M = 17, Z = 10 2 e 8 e Atom D n = 1 n = 2 n = 3M = 7, Z = 3 2 e 1 e Atom E n = 1 n = 2 n = 3M = 34, Z = 17 2 e 8 e 7 e (A) A (B) B (C) C (D) D (E) EBonding:11. In which pair of compounds should the first member be more covalent than the second member?(A) TlCl, TlCl3(B) SnI4, SnF4 (C) LiF, BF3(D) SnF4, CF412. Which is the most complete and best description of a covalent bond?(A)a system of two nuclei with a pair of electrons located exactly midway between both nuclei(B)the attractive force between two atoms of opposite charge(C)a donor bond in which one atom donates an unshared pair to the other(D)a system of two nuclei where each atom donates one electron to the other atom, thus forming a bond13. Which pair of elements is most likely to react to form a covalently bonded species?(A) P and O(B) Ca and O (C) K and S (D) Zn and C14. Which chloride should exhibit the most covalent type of bond?(A) NaCl (B) KCl (C) CaCl2(D) BaCl2(E) BeCl215. The compound of which two elements is most likely to involve covalent bonding?Electronegativities ofUnknown ElementsQ 0.9 X 3.0R 1.0 Z 4.0T 2.8(A)Q and Z (B)R and T (C)T and X (D)R and X (E)R and ZFormulas & Equations:16. Complete and balance the equation for the combustion of ZnS in excess oxygen? ZnS + ? O2  ? ZnO + ?Use no fractional coefficients. The number of moles and the formula of the product containing S are(A) 2S (B) S8(C) SO2(D) 2SO2(E) SO317. Balance the equation for the reaction, using no fractional coefficients.? P + ? HNO3 + ? H2O  ? H3PO4 + ? NOThe ratio of the moles of oxidizing agent to moles of reducing agent in the balanced equation is(A) 5 to 2. (B) 5 to 3. (C) 3 to 5. (D) 2 to 5. (E) 1 to l.18. Balance the equation for the reaction, using no fractional coefficients. 2? Cr2O3 + ? KOH +? O2  ? K2CrO4 + ? H2OThe coefficient of KOH in the balanced equation is(A) 2 (B) 4 (C) 6 (D) 8 (E) 1019. Why is the equation incorrect? Mg3 + N2  Mg3N2(A) Some of the subscripts are incorrectly used.(B) The equation is not balanced.(C) The valence of the nitride ion is incorrect.(D) The valance of the magnesium ion is incorrect.(E) The coefficient of N2 is incorrect.Gases:20. In which gas are the forces between molecules strongest?(A) Ne (B) CH4(C) O2(D) H2O21. The density of a gas is 1.96 g·L–1 at 1.00 atm and 0 °C. What is the density of this gas at 0.855 atm and 25.0 C?(A)0.00276 g·L–1 (B)0.651 g·L–1 (C)1.54 g·L–1 (D)1.82 g·L–122. A 1200 mL sample of helium gas is at a pressure of 350 mmHg and a temperature of 300 K. What volume will this gas sample occupy if the pressure is increased to 700 mmHg and the temperature is increased to 400 K?(A) 450 mL (B) 800 mL (C) 1650 mL (D) 3200 mL23. A sample of nitrogen at pressure P is contained in a sealed syringe with a movable piston. If the volume of the sample were doubled and the absolute temperature tripled, the new pressure of the gas would be(A) 6.0 P (B) 5.0 P (C) 3.5 P (D) 1.5 PIntroductory Concepts:24. When equal volumes of 0.1 M solutions of HCl and NaOH are mixed, the total number of ions present will be approximately(A) twice as great as before mixing. (B) the same as before mixing.(C) half as great as before mixing. (D) 10–7 times as great as before mixing.(E) 10–14 times as great as before mixing.25. Oxygen and ozone have the formulas O2 and O3 respectively. They are(A) isomers. (B) isobars. (C) allotropes. (D) isotopes.26. Which instrument is directly used to determine the relative masses of atoms?(A) spectroscope (B)Geiger counter (C)mass spectrograph (D)microbalance(E)electron microscope27. An enclosed mixture has a mass of 12.69723±0.00003 g, and after a chemical change occurs the mixture has a mass of 12.69724±0.00003 g. These results show that(A)the law of conservation of matter is not always true.(B)the law of conservation of mass is not always true.(C)the mass of the enclosed mixture remains constant within the experimental error of the measurement.(D)the mass of the enclosed mixture does not change.(E)the mass of the enclosed mixture increased.28. The mechanism of electrical conduction in metals is thought to be(A) the same as that in solid electrolytes. (B) the same as that in molten electrolytes.(C) dependent on the movement of ions. (D) dependent on the movement of valence electrons.Laboratory:329. A student determines the mass of an object using a triple beam balance which is sensitive to 0.01 g. When the beam balances, the rider