CHEM 1111 FALL 2017Final LAB EXAM

CHEM 1111 FALL 2017Final LAB EXAM

Name: Dr. Delgado

1) Which gives the correct numbers of protons, neutrons, and electrons in a neutral atom of Sn?

A) 118 protons, 50 neutrons, 118 electrons

B) 118 protons, 118 neutrons, 50 electrons

C) 50 protons, 68 neutrons, 50 electrons

D) 68 protons, 68 neutrons, 50 electrons

E) 50 protons, 50 neutrons, 50 electrons

2) Isotopes are atoms of the same element that have

A) different atomic numbers.

B) the same atomic numbers but different numbers of protons.

C) the same atomic numbers but different numbers of electrons.

D) the same atomic number but different numbers of neutrons.

E) the same atomic mass but different numbers of protons.

Global Outcomes: GO7

3) The correct symbol for the isotope of potassium with 22 neutrons is

A) K. B) K. C) P. D) P. E) K.

4) Given the following: X, X, X, and X. Which are isotopes of each other?

A) X andX are isotopes of each other; and X and X are isotopes of each other.

B) X and X are isotopes of each other.

C) X, X, X, and X are isotopes of each other.

D) None are isotopes of each other.

5) Which of the following is NOT true for the atoms 13N, 14N, and 15N?

A) They all have the same mass number.

B) They are isotopes.

C) They all have the same atomic number.

D) They all have 7 protons.

E) They all have 7 electrons.

6) The elements sodium, magnesium, and silicon

A) are isotopes of each other.

B) are in the same period of elements.

C) have the same number of neutrons.

D) are in the same group.

E) have the same mass number.

7) In this reaction, what is the correct coefficient for hydrogen gas? ? H2 + ? O2 → ? H2O

A) 1 B) 2 C) 3 D) 4 E) 5

Barium chloride and sodium sulfate react according to the following equation.

BaCl2 + Na2SO4 → BaSO4 + 2NaCl

Answer the question(s) that follow about this reaction.

8) How many moles of barium sulfate are produced from 0.100 mole of barium chloride?

A) 0.0100 mole B) 0.100 mole C) 0.200 mole D) 1.00 mole E) 2.00 moles

9) How many grams of barium sulfate can be produced from 20.8 g of barium chloride?

A) 1.37 g B) 2.33 g C) 23.3 g D) 137 g E) 233 g

10) How many grams of barium chloride are needed to make 100. grams of barium sulfate?

A) 44.9 g B) 89.3 g C) 208.3 g D) 233.3 g E) 46.6 g

Answer the question(s) that follow about the following reaction. 2H2O2 → 2H2O + O2

11) How many moles of oxygen gas can 30. g of hydrogen peroxide ( H2O2) produce, if decomposition is complete?

A) 0.50 mole B) 0.88 mole C) 1.0 mole D) 2.0 mole E) 0.44 mole

12) How many grams of water will 100. grams of hydrogen peroxide ( H2O2 ) produce?

A) 3600 g B) 360. G C) 5.88 g D) 52.9 g E) 106 g

13) How many grams of hydrogen peroxide ( H2O2 ) are needed to produce 25.0 g of oxygen?

A) 106 g B) 26.6 g C) 5.88 g D) 25.0 g E) 53.1 g

14) How many moles of hydrogen peroxide ( H2O2) are needed to produce 5.0 moles of water?

A) 1.0 moles B) 2.0 moles C) 4.0 moles D) 5.0 moles E) 8.0 moles

15) Which one of the following is the highest temperature?

A) 38 °C

B) 96 °F

C) 302 K

D) none of the above

E) the freezing point of water

16) Which of the following is (are) the lowest temperature?

A) The freezing point of water B) 5 °C C) 30 °F D) 280 K E) A and D

17) Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide:

CaO (s) + H2O (l) → Ca(OH)2 (s)

In a particular experiment, a 1.50-g sample of CaO is reacted with excess water and 1.48 g of Ca(OH)2 is recovered. What is the percent yield in this experiment?

A) 99 B) 0.99 C) 2.16 D) 74.8 E) 101.2

18) Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide:

CaO (s) + H2O (l) → Ca(OH)2 (s)

A 4.00-g sample of CaO is reacted with 3.86 g of H2O. How many grams of water remains after completion of reaction?

A) 0.00 B) 0.00793 C) 2.57 D) 1.04 E) 0.143

19) Magnesium burns in air to produce magnesium oxide: 2Mg (s) + O2 (g) → 2MgO (s)

When 2.00 g of magnesium burns, the theoretical yield of magnesium oxide is ______g.

A) 2.00 B) 3.32 C) 0.0823 D) 1.66 E) 6.63

20) Magnesium burns in air to produce magnesium oxide: 2Mg (s) + O2 (g) → 2MgO (s)

How many moles of O2 are consumed when 4.11 mol of magnesium burns?

A) 0.169 B) 0.487 C) 4.11 D) 8.22 E) 2.06

21) Lithium and nitrogen react to produce lithium nitride: 6Li (s) + N2 (g) → 2Li3N (s)

How many moles of N2 are needed to react with 0.710 mol of lithium?

A) 4.26 B) 0.710 C) 0.237 D) 2.13 E) 0.118

22) How many liters of air are in a room that measures 10.0 ft x 11.0 ft and has an 8.00 ft ceiling?

1 in. = 2.54 cm (exactly); 1 L = 103 cm3

A) 2.49 × 104 B) 92.8 C) 26.8 D) 2.68 × 107 E) 8.84 × 105

23) The width, length, and height of a large, custom-made shipping crate are 1.20 m, 2.12 m, and

0.54 m, respectively. The volume of the box to correct number of significant figures is ______m3.

A) 1.37376 B) 1.4 C) 1.37 D) 1.374 E) 1.3738

24) The number 0.00430 has ______significant figures.

A) 2 B) 3 C) 5 D) 4 E) 6

25) How many significant figures are in the measurement 5.34 g?

A) 1 B) 2 C) 4 D) 3 E) 5

26) The density of Ag is 10.5 g/cm3. A piece of Ag has a volume of 63.1 cm3 has a mass of _____ g.

A) 663 B) .445 C) 2.25 D) 112 E) 23.6

27) Of the following, only ______is not a metal.

A) Hg B) Se C) V D) Lu E) Y

28) A temperature of 300. K is the same as ______°F.

A) 81 B) 260 C) 711 D) 351 E) 63

29) An ion has 8 protons, 9 neutrons, and 10 electrons. The symbol for the ion is ______.

A) 17O2- B) 17O2+ C) 19F+ D) 19F- E) 17Ne2+

30) What is the formula for perchloric acid?

A) HClO B) HClO3 C) HClO4 D) HClO2 E) HCl

31) The temperature of -25 °C is ______in Kelvins.

A) 138 B) 166 C) 103 D) 298 E) 248

32) The ionization energy of atoms

A) decreases going across a period.

B) decreases going down within a group.

C) increases going down within a group.

D) does not change going down within a group.

E) None of the above.

33) Of the elements: B, C, F, Li, and Na., the element with the largest atomic radius is

A) B. B) C. C) F. D) Li. E) Na.

34) Of the elements: B, C, F, Li, and Na. The element with the highest ionization energy is

A) B. B) C. C) F. D) Li. E) Na.

35) Of the elements: B, C, F, Li, and Na. The element with the most metallic character is

A) B. B) C. C) F. D) Li. E) Na.

36) The octet rule indicates that

A) all of the noble gases have eight total electrons.

B) all of the shells in an atom hold a maximum of 8 electrons.

C) all of the Group A elements have 8 valence electrons.

D) atoms lose, gain, or share valence electrons to have 8 valence electrons.

E) the noble gases react with other compounds to get 8 valence electrons.

37) In a molecule with covalent bonding,

A) oppositely charged ions are held together by strong electrical attractions.

B) atoms of metals form bonds to atoms of nonmetals.

C) atoms of different metals form bonds.

D) atoms are held together by sharing electrons.

E) atoms of noble gases are held together by attractions between oppositely charged ions.

38) Double and triple bonds form because

A) the atoms involved have high electronegativities.

B) single covalent bonds do not give all of the atoms in the molecule eight valence electrons.

C) one of the atoms in the molecule has more than eight valence electrons.

D) the ions involved have charges larger than one.

E) there is at least one hydrogen atom involved in the bond.

39) Choose the best Lewis structure for OCl2.

A) B) C) D) E)

40) The ability of an atom to attract the shared electrons in a covalent bond is its

A) electronegativity. B) bonding ability. C) polarity. D) ionic character. E) nonpolarity.

41) If the electronegativity difference between elements X and Y is 2.1, the bond between the elements X-Y is

A) ionic. B) nonpolar ionic. C) nonpolar covalent. D) polar covalent. E) impossible.

42) A chemical equation is balanced when

A) the total number of molecules is the same in reactants and products.

B) the total number of ions is the same in reactants and products.

C) the sum of the coefficients of the reactants is equal to the sum of the coefficients of the products.

D) the number of atoms of each element is the same in reactants and products.

E) the charge on each atom is the same in reactants and products.

43) Which of the following gives the balanced equation for this reaction?

K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + KNO3

A) KPO4 + CaNO3 + KNO3

B) K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + 3KNO3

C) 2K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + 6KNO3

D) 2K3PO4 + 3Ca(NO3)2 → Ca3(PO4)2 + 6KNO3

E) K3PO4 + Ca(NO3)2 → Ca3(PO4)2 + KNO3

44) In a ______reaction, two or more elements or compounds form one product.

A) decomposition

B) single replacement

C) dehydration

D) double replacement

E) combination

45) The following reaction takes place when an electric current is passed through water. It is an example of a ______reaction. 2 H2O → 2H2 + O2

A) combination

B) single replacement

C) dehydration

D) decomposition

E) double replacement

46) Which of the following properties is NOT a characteristic of the Group 1A(1) elements (alkali metals)?

A) They are shiny.

B) They are good conductors of heat.

C) They react vigorously with water.

D) Most of them are liquids at room temperature.

E) They are good conductors of electricity.

47) The Group 8A(18) elements

A) are unreactive and are rarely found in combination with other elements.

B) are good conductors of electricity.

C) melt at high temperatures.

D) are liquids at room temperature.

E) react vigorously with water.

48) Which of the following is a characteristic of nonmetals?

A) shiny B) malleable C) conductors of heat D) low melting points E)conductors of electricity

49) In an electron-dot structure of an element, the dots are used to represent

A) all of the electrons in the atom.

B) the valence electrons.

C) the electron arrangement.

D) only the electrons that will participate in bond formation.

E) the electrons that the element will gain when it forms a compound.

50) How many valence electrons are in the electron-dot structures for the elements in group 3A(13)?

A) 1 B) 2 C) 3 D) 4 E) 6

51) The number of dots in the electron dot structure of nitrogen is

A) one. B) two. C) three. D) four. E) five.

52) Which of the following is the correct electron-dot structure for carbon?

A) B) C) D) E)

53) What is the classification for this unbalanced reaction? Fe + HCl → FeCl3 + H2

A) dehydration B) combination C) decomposition D) single replacement E) double replacement

54) Which of the following is an oxidation-reduction reaction?

A) CaCl2 + Na2SO4 → CaSO4 + 2NaCl

B) KOH + HNO3 → H2O + KNO3

C) N2 + O2 → 2NO

D) AgNO3 + NaCl → AgCl + NaNO3

E) Al4(SO4)3 + 6KOH → 2 Al(OH)3 + 3K2SO4

55) What is oxidized and what is reduced in the following reaction? 2Al(s) + 3Br2 (g) → 2AlBr3(s)

A) Al is oxidized and Br2 is reduced.

B) AlBr3 is reduced and Br2 is oxidized.

C) Al is reduced and Br2 is oxidized.

D) AlBr3 is reduced and Al is oxidized.

E) AlBr3 is oxidized and Al is reduced.

56) Given the following equation, what is the correct form of the conversion factor needed to convert the number of moles of O2 to the number of moles of Fe2O3 produced? 4Fe(s) + 3O2 (g) → 2Fe2O3(s)

A) B)

C) D) E)

57) What type of reaction is: CH4 + 2O2 → CO2 + 2H2O + 218 kcal?

A) an endothermic reaction

B) an exothermic reaction

C) a single replacement reaction

D) a combination reaction

E) a decomposition reaction

58) How many kcal are produced when 32.0 g of CH4 react? CH4 + 2O2 → CO2 + 2H2O + 218 kcal

A) 218 kcal B) 109 kcal C) 436 kcal D) 6.81 kcal E) 698 kcal

59) If the reaction shown below is exothermic, the energy level of the reactants is ______.

H2 + O2 → 2N2O

A) lower than that of the products

B) higher than that of the products

C) the same as that of the products

D) possibly lower, possibly higher than that of the products

E) higher than the activation energy of the reaction

60) Which measurement describes the pressure of a gas?

A) 315 K B) 1.2 g/L C) 2.5 L D) 725 mmHg E) 0.45 moles

61) At constant temperature, a sample of helium at 760. torr in a closed container was compressed from 5.00 L to 3.00 L. What was the new pressure exerted by the helium on its container?

A) 800. Torr B) 2280 torr C) 15.0 torr D) 3800 torr E) 1270 torr

62) At STP, what is the volume of 4.50 moles of nitrogen gas?

A) 167 L B) 3420 L C) 101 L D) 60.7 L E) 1230 L

63) How many moles of neon occupy a volume of 14.3 L at STP?

A) 36.7 moles B) 32.0 moles C) 6.45 moles D) 0.638 moles E) 1.57 moles

64) A tank contains a mixture of helium, neon, and argon gases. If the total pressure in the tank is 490. mmHg and the partial pressures of helium and argon are 215 mmHg and 102 mmHg, respectively, what is the partial pressure of neon?

A) 0.228 mmHg B) 603 mmHg C) 377 mmHg D) 807 mmHg E) 173 mmHg

65) The molecular geometry of the BrO3- ion is ______.

A) trigonal pyramidal B) trigonal planar C) bent D) tetrahedral E) T-shaped

CHALLENGE Question (5pts)

66) Choose the best electron structure for CH2Cl2.

A)

B)

C)

D)

E)