2007 Release Chemistry SOL Test

Transcription

1 Name: Score: 50 / 50 points (100%) 2007 Release Chemistry SOL Test Multiple Choice Identify the choice that best completes the statement or answers the question. B 1. What is the volume of the liquid in the graduated cylinder? a ml c ml b ml d ml B The lines are marked every 0.5 ml and increases as you go from 10 to 15. D 2. Atoms of the noble gases are generally inert because a. they are too large to react c. they are neutral atoms b. they are not charged d. their outer electron levels are filled C 3. D Noble gases are in group 18 and therefore have 8 valence electrons, which is the maximum an atom can hold. Element Mass in Grams for a Mole of Atoms Ca 40 H 1 O 16 What is the mass of a mole of? file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 1/18

2 a. 57 grams c. 74 grams b. 58 grams d. 114 grams C When the 2 is distributed to the O and H, you will have 1 Ca, 2 O, and 2 H = 40+1x2+2x16=74 C 4. Which of these represents a synthesis reaction? a. c. b. d. C Synthesis is two going into 1 Choice C A is an example of double replacement, B is an example of single replacement, and d is decomposition. C 5. Sulfur is represented by the following Lewis dot structure Which of the elements has the same Lewis structure? a. Chlorine c. Oxygen b. Magnesium d. Phosphorus C Which of the other element are in group 16 with Sulfur? Another way this could be stated is which of the following is in the same column as Sulfur? Either way, it is oxygen. (Cl is in Group 17, Mg is in group 2, and P is in group 15) B 6. A mixture of gases with a pressure of mm Hg contains 60% nitrogen and 40% oxygen by volume. What is the partial pressure of oxygen in this mixture? a mm Hg c mm Hg b mm Hg d mm Hg file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 2/18

3 B 7. B 40% of 800 is 800(0.40) = 320 The equation shows the combustion of butane produced by 12.5 moles of with excess oxygen? a mol c. 125 mol b mol d. 202 mol. How many moles of water can be B mole to mole problem one fraction using the coefficients 12.5 moles C 4 H 10 x =62.5 A 8. The formula for magnesium chloride is a. c. b. d. A Metal and nonmetal = ionic, which means switchy switchy Mg has a +2 on periodic table, Cl has a 1 on periodic table so switch the numbers and get Mg 1 Cl 2 D 9. What are the numbers of protons, neutrons, and electrons in an isotope of titanium with a mass number of 50? a. 22 p, 22 n, 28 e c. 50 p, 22 n, 50 e b. 28 p, 22 n, 22 e d. 22 p, 28 n, 22 e D Look up Titanium (Ti) on periodic table, it has a atomic number is 22. Atomic number = protons and if neutral (like in this case since no charge is mentioned) electron (negative) must equal protons (positive). So 22 = p = e. To get n, take 50 22=28 file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 3/18

4 A KJ/mole 23.4 KJ/mole Molar Heat of Vaporization Water and ammonia have different molar heats of vaporization. The best interpretation, at the molecular level, is that water molecules a. have stronger intermolecular attractions b. occupy larger molecular volumes c. set up stronger repulsive nuclear forces d. collide more frequently with each other A Higher heat of vaporization means it is a liquid longer, which means its particles hold onto each other longer. Therefore, stronger intermolecular attractions. D 11. Which of these statement describes what happens to the molecules of a solid as the temperature is lowered to absolute zero ( 273ºC)? a. They begin to take up more space. b. They become farther apart. c. Their kinetic energy gradually increases to a maximum. d. Their motion gradually decreases and eventually stops. D Temperature = average kinetic energy = motion. As temperature is decreased, motion will also decrease until it stops completely A 12. A sample of iron has a volume of 10.0 ml. The density of iron is 7.87 g/ml. Which is the correct expression to calculate the mass of the sample using dimensional analysis? a. c. b. d. A D=m/V, if we solve for m, we get m=vd. Plug in numbers, 10mL x 7.87g/mL ( ) file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 4/18

5 Can t remember the density formula? Two options can be eliminated by dimensional analysis. If the math is done on c and d, the units would be ml 2 /g and since the unit of mass is g, these could be eliminated. Which leaves choice b to eliminate, which can be done by looking at the given density and realizing that the 7.87 goes where the g goes. B 13. What mass of nitrogen is required to react with 16 grams of oxygen? a. 2.8 g c. 14 g b. 5.6 g d. 56 g B Long stoichiometry problem grams to moles to moles to grams molar mass of O 2 use coefficients (going to on top, given on bottom) x molar mass of N 2 16 grams O 2 x x x = 5.6 grams A 14. Hydrogen chloride can be formed from hydrogen and chlorine as shown in the reaction. Chlorine and fluorine are located in the same group in the periodic table. If the reaction were performed with fluorine instead of chlorine, how many moles of H 2 would be required to balance the equation? a. 1 c. 4 b. 2 d. 8 A Fluorine is also a diatomic, so the only thing that would change in the balanced equation is the Cl would be a F (H 2 + F 2 2HF + heat), so H 2 file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 5/18

6 still has a 1 in front of it. Remember the coefficients represent moles so the answer is 1. D 15. The correct name for Mg 3 (PO 4 ) 2 is a. magnesium phosphite c. magnesium(iii) phosphate b. trimagnesium phosphate d. magnesium phosphate D Mg metal with only 1 oxidation number (only a +2 in the upper right corner) no roman numeral PO 4 polyatomic ion (phosphate) Therefore ionic compound no prefixes So, is it phosphate or phosphite? Can t remember, I would go with phosphate since it is in three of the answers A 16. How many protons are in an atom represented by? a. 88 c. 220 b. 132 d. 308 A Protons (and the electrons) are equal to the atomic number, which is the bottom number. So the answer is 88 D 17. (The top number is the mass number, so if it asked for neutrons = =132) file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 6/18

7 Four students each took three temperature readings of a sample of water. The actual temperature of the sample was 80.0ºC. Which student s measurements were both accurate and precise? a. Student 1 c. Student 3 b. Student 2 d. Student 4 D Which group had all of their measurements around 80 degrees? Student 4 B 18. According to the kinetic molecular theory of gases, molecules of an ideal gas a. travel in curved lines of motion c. are separated by small distances b. undergo elastic collisions d. have strong forces between them B a not true assumes straight lines b true c not true assumes large distances compared to the size of the molecules d not true assumes no attraction between molecules D 19. What is the molar mass of beryllium oxide (BeO)? a. 12 g/mol c. 24 g/mol b. 13 g/mol d. 25 g/mol D Be = 9.0 x 1 = 9.0 O = 16 x 1 = D 20. Catalytic converters made of palladium (Pd) reduce automobile pollution by catalyzing the reaction between unburned hydrocarbons and oxygen. How does Pd increase the rate of this reaction? a. By cooling the reactants b. By splitting the oxygen atoms c. By giving the hydrocarbons a negative charge d. By decreasing the activation energy D Anytime you see a question about catalyst, remember catalysts lower the activation energy file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 7/18

8 C 21. A chloride ion (Cl ) has the same number of electrons as a neutral atom of a. fluorine c. argon b. sulfur d. bromine C Cl 1 has one more electron (remember electrons are negative so if you add one, it would make it more negative) than a Cl atom. So, if you add an electron, it would have 18 electrons like Ar D 22. Which of these is the proper method for using a thermometer to measure the temperature of liquid in a beaker? C 23. a. Method F c. Method H b. Method G d. Method J D You want the bulb of the thermometer in the very center of the solution. file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 8/18

9 Which of the following is most likely the electronegativity value for chlorine? a. 2.3 c. 3.0 b. 2.7 d. 4.2 C Electronegativity increase as you go to the right and decreases as you go down (which can be seen on this diagram) So, it needs to be less than 4 but more than 2.8. D 24. Which compound has a covalent bond? a. CaI 2 c. NaCl b. KBr d. NO C 25. D Which of them is all nonmetals Ca, K and Na are all metals, so a,b, and c are eliminated. If 5.0 moles of C 3 H 8 react, how many molecules of water are formed? a. 3.0 x c. 1.2 x b. 4.8 x d. 2.4 x C Going from moles C 3 H 8 to molecules H 2 O, so you need two fractions moles to moles (coefficients, given on bottom) than moles to molecules (Avogadro s number, 6.02 x ) file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 9/18

10 5.0 moles C 3 H 8 x x =1.204x10 25 B 26. Which of these best describes sublimation? a. A solid changing to a liquid phase b. A solid changing to a gaseous phase c. A gas filling the space in its container d. A liquid taking the shape of its container B sublimation is a solid to a gas C 27. If the difference in electronegativity between atoms of different non metals is small, the atoms of the two non metals will most likely a. form an ionic bond c. form a covalent bond b. form a hydrogen bond d. form a metallic bond C key word non metals bonds between nonmetals are covalent [two metals metallic, a non metal and metal ionic, hydrogen bonding is not a intramolecular (within a molecule) bond] C 28. The role of a catalyst is to affect a. electronegativity c. activation energy b. heat content d. ionization energy C Anytime you see a question about catalyst, remember catalysts lower the activation energy C 29. Which of these best describes the difference between the formulas for nitrogen monoxide and nitrogen dioxide? a. Nitrogen monoxide has one more atom of nitrogen. b. Nitrogen dioxide has one fewer atom of oxygen. c. Nitrogen monoxide has one fewer atom of oxygen. d. Nitrogen dioxide has one more atom of nitrogen. file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 10/18

11 C nitrogen monoxide is NO (mono is one) nitrogen dioxide is NO 2 (di is two) So, nitrogen monoxide has one fewer atom of oxygen. D 30. Sulfuric acid (H 2 SO 4 ) is spilled on a laboratory bench. Which chemical would be useful for neutralizing the acid? a. Aluminum chloride (AlCl 3 ) c. Silver iodide (AgI) b. Potassium nitrate (KNO 3 ) d. Sodium bicarbonate (NaHCO 3 ) D Looking for a weak base. In this case, NaHCO 3 is a conjugate base of a weak acid (H 2 CO 3, acetic acid), if not sure, remember that sodium bicarbonate is used to neutralize vinegar to make a fizzy volcano demonstration. B 31. When compared to sulfur 32, sulfur 34 has more a. protons c. energy levels b. neutrons d. bonding configurations B 32. B The number after the name represent the mass number of the isotope. The mass number is equal to the protons + neutrons. To change the mass of an element without changing the element, you must change the neutrons. file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 11/18

12 The graph shows five data points collected in an investigation of the relationship between the concentration of alcohol dissolved in water and its density. The relationship was expected to be linear. Which of the data points most likely resulted from an error in procedure? a. 1 c. 4 b. 2 d. 5 B 2 is the only point not in the line. A good way to solve this problem on the real SOL test would be the straight edge feature and connect the dots. C 33. What is the chemical name for the compound P 3 N 5? a. Triphosphorus nitride c. Triphosphorus pentanitride b. Phosphorus(III) nitride d. Pentaphosphorus trinitride C P and N are both nonmetal [right of stair step (shown on periodic table under Po and At)] covalent must use prefixes (no switchy switchy or roman numerals) Since both have subscripts, both need a prefix. 3 is tri, 5 is penta D 34. In NHO 3, the oxidation state of hydrogen is +1 and the oxidation state of oxygen is 2. Therefore, the oxidation state of nitrogen is a. 1 c. +4 b. +3 d. +5 file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 12/18

13 D x+1 6=0, so x=+5/1(subscript) = +5 A 35. The graph shows the phase diagram of a substance. At which point on the diagram do the solid, liquid, and gas phases coexist simultaneously? a. 1 c. 3 b. 2 d. 4 A This question is asking where the triple point is, so at what point do all three lines meet? 1 B 36. The partial pressures of the gases that comprise air are shown in the table. file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 13/18

14 If the total atmospheric pressure is mm Hg, what is the partial pressure of CO 2? a mm Hg c mm Hg b mm Hg d mm Hg B All the partial pressures must equal the total pressure. So, 760 = x x = 0.24 C 37. Which is the safest practice when heating the contents of a test tube over a flame? a. Wearing long hair down b. Having safety goggles within reach c. Pointing the test tube away from people d. Keeping the test tube securely stoppered C 38. C a not safe because hair can catch on fire b not safe because they should be on the face covering the eyes c safe d not safe because pressure will build up and test tube can explode When the equation is correctly balanced, the coefficient of H 2 SO 4 is a. 1 c. 3 b. 2 d. 4 C file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 14/18

15 2 Al + 3 H 2 SO 4 1 Al 2 (SO 4 ) H 2 A 39. Which graph shows the relationship between temperature and volume as described in the Charles Law? a. Graph A c. Graph C b. Graph B d. Graph D A Can t remember what Charles Law states, not problem. The problem tells us we are dealing with temperature and volume. As temperature increase, the volume will get bigger too and in a linear way. So, which graph shows the temperature and volume both going up at the same time? A D 40. Place the following models about the structure of the atom in the order that they were developed: 1. Planetary model 2. Quantum mechanical model 3. Solid sphere model a. 1, 3, 2 c. 2, 3, 1 b. 1, 2, 3 d. 3, 1, 2 D Dalton and Democritus came first with the solid sphere (fireball model) (JJ Thomson plum pudding) (Rutherford positive middle/electrons somewhere outside nucleus) Bohr planetary model file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 15/18

16 Schrodinger electron cloud aka quantum mechanical model C 41. The boiling point of ethanol is 78.3 C. The boiling point of ethanol on the Kelvin scale is approximately a. 26 K c. 351 K b. 178 K d. 451 K C 42. C To go from C to K, add 273 (Remember that K is always bigger than C) The reaction is which type of chemical reaction? a. Single replacement c. Synthesis b. Double replacement d. Decomposition C Two compounds combine into 1 = synthesis A 43. What does ph measure? a. Hydrogen ion concentration c. Acid density b. Hydroxide ion concentration d. Base density B 44. A ph stands for the power of hydrogen so it is the concentration of the hydrogen ion concentration The subscript of oxygen in the product should be a. 2 c. 10 b. 5 d. 20 B file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 16/18

17 We have 10 O s on the left so we need 10 O s on the right. So, 2x=10. Solving for x=5. B 45. The proper scientific notation for 565,000,000,000 is a..565 x c x b x d. 565 x 10 9 B When numbers are written in scientific notation, the number in front of the x 10 must be a nonzero number (1 9) C 46. What are shared in covalent bonds? a. Cations c. Electrons b. Protons d. Antons C In all bonds, electrons are what are shared or transferred. C 47. A 0.67 L solution of ammonium sulfate, (NH 4 ) 2 SO 4, contains 0.81 mole of the solute. What is the approximate molarity of the solution? a M c. 1.2 M b M d. 1.5 M C Molarity = moles / Liters M = 0.81 mol / 0.67 L = 1.21 M B 48. Which of these is the percent of error in evaluating the molecular mass of a compound if the experimental value was amu and the known value was amu? a. 1.0% c. 3.3% b. 2.1% d. 4.2% B % error = (theor exp)/theor x 100 = ( )/107.5 x 100 = 2.14% file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 17/18

18 A 49. What is the correct formula for aluminum chloride? a. AlCl 3 c. Al 2 Cl 3 b. Al 3 Cl d. AlCl C 50. A Aluminum is a metal (only has a +3 in the top corner) and chloride is a nonmetal (so it is the 1). Therefore, ionic compound, which means switchy switchy. 1 goes to Al, 3 goes to Cl. NO 2 and N 2 O 4 undergo the reaction shown. When a sealed container of NO 2 reaches chemical equilibrium, which must be true? a. No N 2 O 4 is present. b. No chemical reactions are occurring. c. The rates of the forward and reverse reactions are equal. d. The maximum number of molecules has been reached. C Equilibrium means rate forward equals rate in reverse. file:///f:/sol%20review%20topics/2007%20sol%20exam/2007_sol_test.htm 18/18