CHM 2040 Final Review Carolina France

  1. The statement “when iron rusts in a closed container, the mass of the container and its contents do not change” is a/an:

a. Observation

b. Law

c. Theory

d. Hypothesis

  1. Express 98.6 °F in K (body temperature)

a. 37.0 K

b. 310. K

c. 375 K

d. 310.2 K

  1. Classify VEGETABLE SOUP as a pure substance or a mixture. If it is a pure substance, classify it as an element or a compound. If it is a mixture, classify it as a homogeneous or heterogeneous.

a. Mixture, compound

b. Pure substance, mixture

c. Mixture, heterogeneous

d. Pure substance, compound

  1. Glycerol is a syrup liquid often used in cosmetics and soaps. A 3.25 L sample of pure glycerol has a mass of 4.10 x 103 g. What is the density of glycerol in g/cm3?

a. 0.793 g/cm3

b. 1262 g/cm3

c. 1.26 x 106 g/cm3

d. 1.26 g/cm3

  1. Calculate to the correct number of significant figures: (24.6681 x 2.38) + 332.58

a. 391.28

b. 391.29

c. 391.3

d. 391.290

  1. The average US farm occupies 435 acres. How many square miles is this?

a. 3.59 mi2

b. 0.680 mi2

c. 52.7 mi2

d. 0.679 mi2

  1. An acetaminophen suspension for infants contains 80 mg/0.80 mL suspension. The recommended dose is 15 mg/kg body weight. How many mL of this suspension should be given to an infant weighing 14 lb?

a. 2.1 mL

b. 42 mL

c. 0.95 mL

d. None of the above

  1. Bromine has two naturally occurring isotopes (Br-79 and Br-81) and has an atomic mass of 79.904 amu. The mass of Br-81 is 80.9163 amu, and its natural abundance is 49.31%. Calculate the mass and natural abundance of Br-79.

a. 80.00 g/mol

b. 79.91 amu

c. 78.92 amu

d. 78.92 g/mol

  1. A hydrogen-filled balloon is ignited and 1.50 g of hydrogen is reacted with 12.0 g of oxygen. How many grams of water vapor form? (Assume that water vapor is the only product.)

a. 13.5 g H2O

b. 12.0g H2O

c. 1.50 g H2O

d. 10.5 g H2O

  1. A ____ is an atom that loses electrons and obtains a _____ charge
  1. cation; positive
  2. cation; negative
  3. anion; negative
  4. anion; positive
  1. Which statements are consistent with Dalton’s atomic theory as it was originally stated?
  1. Sulfur and oxygen atoms have the same mass.
  2. The formation of a compound often involves the destruction of one or more atoms.
  3. Potassium and chlorine atoms combine in a 1:1 ratio to form potassium chloride.
  4. Lead atoms can be converted into gold.
  1. Which pair of elements do you expect to be most similar?

a. nitrogen and oxygen

b. titanium and gallium

c. lithium and sodium

d. germanium and arsenic

e. argon and bromine

  1. How many carbon atoms are there in a diamond (pure carbon) with a mass of 52 mg?
  1. 2.6 x 1024 atoms
  2. 1.0 x 10-24 atoms
  3. 7.2 x 10-27 atoms
  4. 2.6 x 10-21 atoms
  1. A 7.83 g sample of HCN contains 0.290 g of H and 4.06 g of N. Find the mass of carbon in a sample of HCN with a mass of 3.37 g.
  1. 3.48 g C
  2. 1.50 g C
  3. 0.110 g C
  4. None of the above
  1. What type of compound is SnF4?

a. Acid

b. Ionic

c. Molecular

d. Metallic

16. Based on the previous answer name the compound properly

a. Tin fluoride

b. Tin (II) fluoride

c. Tin (IV) fluoride

d. Tin tetrafluoride

17.How many moles of hydrogen are in 0.117 mol of dinitrogen tetrahydride (hydrazine)?

a. 0.117 mol

b. 0.468 mol

c. 0.234 mol

d. None of the above

18.A compound containing selenium and fluoride is decomposed in the laboratory and produces 2.231 g of selenium and 3.221 g of fluorine. Calculate the empirical formula of the compound

a. SeF

b. SeF2

c. SeF4

d. SeF6

19.How many hydrogen atoms are in each of the following formulas respectively? H3PO4, Na2HPO4, Ca(HCO3)2, and Ba(C2H3O2)2

a. 3, 1, 1, 3

b. 3, 1, 2, 6

c. 3, 1, 2, 2

d. 3, 1, 1, 6

20.A compound has an empirical formula CH2O and a formula mass of 120.10 amu. What is the molecular formula of the compound?

a. CH2O

b. C4H8O4

c. C2H4O2

d. C3H6O3

21.Covalent compounds

a. typically consist of a metal and a nonmetal attracted to each other by electrostatic forces

b. typically consist of a metal and a nonmetal held together by shared electrons

c. form when two nonmetals share electrons upon forming a chemical bond

d. form when two metals share electrons

22.What are the correct coefficients when the chemical reaction is balanced? ___Ca(OH)2 + ___H2CO3 ___H2O + ___CaCO3

a. 1, 3, 2, 1

b. 1, 1, 2, 1

c. 1, 2, 1, 1

d. 1, 3, 1, 3

23.______is the numerical relationships between amounts of reactants and products in a balanced chemical equation.

  1. Reaction stoichiometry
  2. Chemical reaction
  3. Limiting reagent
  4. None of the above

24. For the precipitation reaction, calculate how many grams of the first reactant are necessary to completely react with 55.8 g of the second reactant.

2 KI(aq) + Pb(NO3)2(aq) ¡ PbI2(s) + 2 KNO3(aq)

  1. 55.8 g
  2. 55.9 g
  3. 28.0 g
  4. 18.8 g

25.For the reaction shown, calculate the theoretical yield of the product (in grams) when starting with 2.4 g Ti and 1.6 g F2

Ti(s) + 2 F2( g) ¡ TiF4(s)

  1. 3.8 g F2
  2. 3.8 g TiF4
  3. 2.6 g TiF4
  4. 2.6 g Ti

26.Write a molecular equation for the precipitation reaction that occurs (if any) when aqueous sodium chloride and aqueous lead(II) acetate is mixed. If no reaction occurs, write “NO REACTION.” sodium chloride and lead(II) acetate

  1. 2 NaCl(aq) + Pb(C2H3O2)2(aq) + 2NaC2H3O2(aq) + PbCl2(s)
  2. NaCl(aq) + Pb(C2H3O2)2(aq) + NaC2H3O2(aq) + PbCl2(s)
  3. 2 NaCl(aq) + Pb2(C2H3O2)(aq) + 2NaC2H3O2(aq) + PbCl(s)
  4. 2 NaCl(aq) + PbC2H3O2(aq) + 2NaC2H3O2(aq) + PbCl2(s)

27.Complete and balance the gas-evolution equation.

HNO3(aq) + Na2SO3(aq) 

  1. H2SO3(aq) + 2NaNO3(aq)
  2. H2O(l) + SO2(aq)
  3. 2NaNO3(aq) + H2O(l) + SO2(aq)
  4. This equation does not form a gas

28.What is the oxidation state of Cr in dichromate?

  1. +6
  2. +3
  3. +2
  4. +1

29.Which of the following is TRUE regarding the following reaction?

F2(g) + 2I-(aq) --> I2(s) + 2F-(aq)

  1. Flourine gets oxidized
  2. Iodide ions lose electrons
  3. Iodine is the reducing agent

A) I only

B) II only

C) III only

D) II and III only

E) I, II, and III

30.Which of the following is NOT a state function?

  1. Pressure
  2. Temperature
  3. Internal energy
  4. Altitude
  5. Work

31.Convert 4.99 x 103 kJ to kWh

  1. 1.80 x 1010 kWh
  2. 1.38 kWh
  3. 4.99 x 106 kWh
  4. 1.80 x 104 kWh

32.A system absorbs 196 kJ of heat and the surroundings do 117 kJ of work on the system. What is the change in internal energy of the system?

  1. 313 kJ
  2. -313 kJ
  3. 79 kJ
  4. -79 kJ

33.A gas is compressed from an initial volume of 5.55 L to a final volume of 1.22 L by an external pressure of 1.00 atm. During the compression the gas releases 124 J of heat. What is the change in internal energy of the gas?

  1. 439 J
  2. 315 J
  3. 4.33 J
  4. -439 J

34.How much heat is required to warm 1.50 kg of sand from 25.0 °C to 100.0 °C? (specific heat capacity for sand is 0.84 J/gC)

  1. 94.5 J
  2. -95.4 J
  3. 9.5 x 104 J
  4. -9.5 x 104 J

35.True/False: Chemical heat packs contain iron filings that are oxidized in an exothermic reaction

36.Which of the following is an exothermic reaction?

  1. Isopropyl alcohol evaporating from skin
  2. The reaction that occurs in a chemical cold pack used to ice athletic injuries
  3. Melting ice cubes
  4. Natural gas burning on a stove

37.Charcoal is primarily carbon. Determine the mass of CO2 produced by burning enough carbon (in the form of charcoal) to produce 5.00 x 102 kJ of heat.

C(s) + O2( g)  CO2( g) ∆H° rxn= -393.5 kJ

  1. 82.1 g CO2
  2. 55.9 g CO2
  3. 112 g CO2
  4. 42.2 g CO2

38.A 32.5-g iron rod, initially at 22.7 °C, is submerged into an unknown mass of water at 63.2 °C, in an insulated container. The final temperature of the mixture upon reaching thermal equilibrium is 59.5 °C. What is the mass of the water?

  1. 12.9 g H2O
  2. 48.8 g H2O
  3. 90.2 g H2O
  4. 34.7 g H2O

39.When 0.514 g of biphenyl (C12H10) undergoes combustion in a bomb calorimeter, the temperature rises from 25.8 °C to 29.4 °C. Find ∆Erxn for the combustion of biphenyl in kJ/mol biphenyl. The heat capacity of the bomb calorimeter, determined in a separate experiment, is 5.86 kJ/°C.

  1. -21.096 kJ
  2. -6.3 x 103 kJ/mol
  3. 3.3332 x 10-3 kJ/mol
  4. -21.096 kJ/mol

40.Consider this reaction: A + 2B  C + 3D ∆H = 155 kJ

Determine ∆H for the following: 3A + 6B  3C + 9D

  1. 465 kJ
  2. 155 kJ
  3. 310 kJ
  4. -115 kJ

41.Calculate ∆Hrxn for the reaction:

5 C(s) + 6 H2(g)  C5H12(l)

Use the following reactions and given ∆H’s:

C5H12(l) + 8 O2(g)  5 CO2(g) + 6 H2O(g)∆H = -3244.8 kJ

C(s) + O2( g)  CO2( g) ∆H = -393.5 kJ

2 H2( g) + O2( g) 2 H2O( g)∆H = -483.5 kJ

  1. -4122 kJ
  2. -824.4 kJ
  3. -206.1 kJ
  4. -173.2 kJ

42.______of a system is the sum of the internal energy of the system and the product of pressure and volume.

  1. Entropy
  2. Enthalpy
  3. Specific heat capacity
  4. Molar heat capacity

43.A bomb calorimeter has constant _____ and is used to measure ______for combustion reactions

  1. Volume; ∆H
  2. Volume; ∆E
  3. Pressure; ∆H
  4. Pressure; ∆E

44.Which describes an endothermic reaction?

  1. ∆H is positive; heat is being released
  2. ∆H is negative; heat is being released
  3. ∆H is negative; heat is being absorbed
  4. ∆H is positive; heat is being absorbed