Practice+Problems

1) The appropriate number of significant figures in the result of 15.234 × 15.208 is A. 2 B. 3 C. 4 D. 5 E. 6

2) As part of an experiment to determine the density of a new plastic developed in her laboratory, Sara Ann Dippity measures the volume of a solid sample. Her four trials yield volumes of 12.37 cm3, 12.41 cm3, 12.39 cm3, and 12.38 cm3. Measurements of other scientists in the lab give an average volume of 12.49 cm3. Which of the following statements represents the best analysis of the data? A. Sara's results have low precision and high accuracy. B. Sara's results have high precision and high accuracy. C. Sara's results have greater precision than accuracy. D. Sara's results have greater accuracy than precision. E. Sara has been using a faulty instrument to measure the volume.

3) Which one of the following is a "substance" in the sense of the word as used in your textbook? A. air B. tap water C. sea water D. water E. toothpaste

4) Which of the following is heterogeneous? A. Aluminum B. Copper C. veggie soup D. milk E. Kool-aid

5) Rutherford bombarded gold foil with alpha (α) particles and found that a small percentage of the particles were deflected. Which of the following was not accounted for by the model he proposed for the structure of atoms? A. the small size of the nucleus B. the charge on the nucleus C. the total mass of the atom D. the existence of protons E. the presence of electrons outside the nucleus

6) Who is credited with discovering the atomic nucleus? A. Dalton B. Gay-Lussac C. Thomson D. Millikan E. Rutherford

7) Which of the following is a correct set of quantum numbers for an electron in a 5f orbital? A. n = 5, l = 3, ml = +1 B. n = 5, l = 2, ml = +3 C. n = 4, l = 3, ml = 0 D. n = 4, l = 2, ml = +1 E. n = 5, l = 4, ml = 3

8) Select the correct electron configuration for Te. A. [Kr]5s25p64d8 B. [Kr]5s25d105p4 C. [Kr]5s24d105p6 D. [Kr]5s24f14 E. [Kr]5s24d105p4

9) Which of the following elements will form a cation with a +2 charge? A. Si B. Sr C. Ga D. Cs E. S

10) The substance, KClO3, is a strong oxidizer used in explosives, fireworks, and matches. What is its name? A. potassium chlorite B. potassium chloride C. potassium(I) chlorite D. potassium(I) chlorate E. potassium chlorate

11) Which of the following elements is the most electronegative? A. Ne B. Rb C. P D. I E. Cl

12) Select the best Lewis structure for ClCN. A. a B. b C. c D. d E. e

13) Balance the following equation for the combustion of benzene: C6H6(l) + O2(g) → H2O(g) + CO2(g) A. C6H6(l) + 9O2(g) → 3H2O(g) + 6CO2(g) B. C6H6(l) + 9O2(g) → 6H2O(g) + 6CO2(g) C. 2C6H6(l) + 15O2(g) → 6H2O(g) + 12CO2(g) D. C6H6(l) + 15O2(g) → 3H2O(g) + 6CO2(g) E. 2C6H6(l) + 9O2(g) → 6H2O(g) + 12CO2(g)

14) Predict the product(s) for the following reaction. MgCO3(s) A. MgO2(s) + CO(g) C. Mg(s) + CO2(g) + O2(g) D. Mg2+(s) + CO2(g) + O2(g) E. No reaction occurs.
 * B**. MgO(s) + CO2

15) Aluminum reacts with oxygen to produce aluminum oxide which can be used as an adsorbent, desiccant or catalyst for organic reactions. 4Al(s) + 3O2(g) → 2Al2O3(s)

A mixture of 82.49 g of aluminum ( = 26.98 g/mol) and 117.65 g of oxygen ( = 32.00 g/mol) is allowed to react. Identify the limiting reactant and determine the mass of the excess reactant present in the vessel when the reaction is complete. A. Oxygen is the limiting reactant; 19.81 g of aluminum remain. B. Oxygen is the limiting reactant; 35.16 g of aluminum remain. C. Aluminum is the limiting reactant; 16.70 g of oxygen remain. D. Aluminum is the limiting reactant; 35.16 g of oxygen remain. E. Aluminum is the limiting reactant; 44.24 g of oxygen remain.

16) Terephthalic acid, used in the production of polyester fibers and films, is composed of carbon, hydrogen, and oxygen. When 0.6943 g of terephthalic acid was subjected to combustion analysis it produced 1.471 g CO2 and 0.226 g H2O. If its molar mass is between 158 and 167 g/mol, what is its molecular formula? A. C4H6O7 B. C6H8O5 C. C7H12O4 D. C4H3O2 E. C8H6O4

17) Lead (II) nitrate is a poisonous substance which has been used in the manufacture of special explosives and as a sensitizer in photography. Calculate the mass of lead in 139 g of Pb(NO3)2. A. 107 g B. 90.8 g C. 87.0 g D. 83.4 g E. 62.6 g

18) Potassium fluoride is used for frosting glass. Calculate the molarity of a solution prepared by dissolving 78.6 g of KF in enough water to produce 225 mL of solution. A. 0.304 M B. 0.349 M C. 1.35 M D. 3.29 M E. 6.01 M

19) A sample of oxygen gas has its absolute temperature halved while the pressure of the gas remained constant. If the initial volume is 400 mL, what is the final volume? A. 20 mL B. 133 mL C. 200 mL D. 400 mL E. 800 mL

20) "The volume of an ideal gas is directly proportional to its absolute temperature at constant pressure and number of moles" is a statement of Law. A. Charles's B. Boyle's C. Amontons's D. Avogadro's E. Dalton's

21) What is the pH of a 0.75 M HNO3 solution? A. 0.12 B. 0.29 C. 0.63 D. 0.82 E. > 1.0

22) What is the [OH-] for a solution at 25°C that has [H3O+] = 2.35 × 10-3 M? A. 4.26 × 10-5 M B. 2.35 × 10-11 M C. 4.26 × 10-12 M D. 2.35 × 10-17 M E. none of these choices is correct

23) Calculate q when 28.6 g of water is heated from 22.0°C to 78.3°C. A. 0.385 kJ B. 1.61 kJ C. 6.74 kJ D. 9.37 kJ

24) Benzene is a starting material in the synthesis of nylon fibers and polystyrene (styrofoam). Its specific heat capacity is 1.74 J/(g·C). If 16.7 kJ of energy is absorbed by a 225-g sample of benzene at 20.0°C, what is its final temperature? A. -22.7°C B. 36.7°C C. 42.7°C D. 62.7°C E. none of these choices is correct

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