Chemistry Final Exam

A 4.0 L sample of N2(g) at 760 mmHg is compressed, at constant temperature, to 3.2 atm. What is the final gas volume? a) 1.3 L b) 950 L c)13 L d) 59 L e) 0.77 L

A) 1.3 L

The mass of a flask is 38.1346 g empty and 63.1769 g when filled with water. When the flask is filled with an unknown liquid, its mass is 75.5778 g. Determine the density of the unknown liquid, in g/mL. (density H2O = 1.000 g/mL) A) 1.495 B) 1.657 C) 0.6688 D) 1.982 E) can't determine from the data given

A) 1.495

If 5.97 mL of a solution contains 2.54 mg of sodium ion, what is the molarity of the sodium chloride solution? a) 1.85 × 10-2 M b) 0.425 M c) 0.102 M d) 7.28 × 10-3 M e) 1.85 × 10-5 M

A) 1.85 x 10^-2 M

How many protons, neutrons, and electrons are in A) 12 protons, 10 electrons, 12 neutrons B) 12 protons, 12 electrons, 12 neutrons C) 24 protons, 10 electrons, 12 neutrons D) 10 protons, 12 electrons, 24 neutrons E) 12 protons, 12 electrons, 24 neutrons

A) 12 protons, 10 electrons, 12 neutrons

How many neutrons are there in the nucleus of a 232Th atom? A) 142 B) 90 C) 151 D) 232 E) 81

A) 142

Convert 66 degrees celsius to Fahrenheit A) 150 B) 69 C) 87 D) 201 E) 188

A) 150

How many photons of light with frequency 5.50 × 1015 Hz are required to provide 1 kJ of energy? a) 2.74 × 10^20 photons b) 4.56 × 10^-4 photons c) 1.65 × 10^44 photons d) 3.64 × 10^-18 photons e) 3.64 × 10^-16 photons

A) 2.74 x 10^20

Cyclohexanol, C6H12O, has a heat of combustion (qrxn) of -890.7 kcal/mol. 0.708 g of cyclohexanol undergoes complete combustion in a bomb calorimeter that has a heat capacity of 2.70 kcal/°C. What is the final temperature if the initial water temperature is 27.0 °C? a) 29.3 °C b) 27.4 °C c) 24.7 °C d) 26.6 °C e) 31.4 °C

A) 29.3 degrees C

A sample of pure carbon weighing 1.48 g was burned in an excess of air. The mass of carbon dioxide, the sole product, was 5.42 g. In a second experiment, 11.62 g of carbon dioxide was obtained. What mass of carbon was burned? A) 3.17 g B) 42.6 g C) 3.54 g D) 0.866 g E) 11. 6g

A) 3.17 g

If 8.52 g each of zinc, potassium dichromate, and sulfuric acid are reacted by the reaction below, how many grams of potassium dichromate will be left unreacted? 4 Zn + K2Cr2O7 + 7 H2SO4→ 4 ZnSO4 + 2 CrSO4 +K2SO4 + 7 H2O a) 4.87 b) 1.05 c) 3.65 d) 2.84 e) 7.30

A) 4.87

What is the total pressure exerted by a mixture of 0.250 moles N2 and 0.400 moles He at 27 °C in a 3.00 L container ? a) 5.33 atm b) 2.05 atm c) 1.23 atm d) 16.0 atm e) 3.28 atm

A) 5.33 atm

Naturally occurring chlorine consists of the two isotopes: chlorine-35 and chlorine-37. The atomic mass for chlorine is approximately 35.5. What are reasonable estimates of the relative percentages of chlorine-35 and chlorine-37, respectively? A) 75, 25 B) 50, 50 C) 67, 33 D) 25, 75 E) 33, 67

A) 75, 25

Which of the following pairs of aqueous solutions will give a precipitate when mixed? a) K3PO4 and CaCl2 b) AgNO3 and Ca(ClO4)2 c) NaCl and Hg(CH3COO)2 d) NaClO4 and Ba(OH)2

A) K3PO4 and CaCl2

Crystals from evaporation of urine analyze to 22.6% phosphorus. Which compound is probably present? A) NaNH4HPO4 B) (NH4)3PO4 C) Ca3(SO4)2 D) Na3PO4 E) H3PO4

A) NaNH4HPO4

12.5 mL of 0.280 M HNO3 and 5.0 mL of 0.920 M KOH are mixed. Is the resulting solution acidic, basic or neutral? a) Basic b) Neutral c) Acidic d) None of these e) HNO3 and KOH do not mix

A) basic

2.24 L NH3(g) at 2.0 atm and 0 °C: a) contains 3.6 × 10^23 H atoms b) contains 3.6 × 10^23 N atoms c) weighs 1.70 g d) contains 6.02 × 10^22 molecules of NH3 e) contains 0.050 mole NH3

A) contains 3.6 x 10^23 H atoms

Calculate ΔU for a system that loses 475 kJ of heat and does 155 kJ of expansion work on the surroundings a) +320 kJ b) -630 kJ/mol c) -320 kJ d) +630 kJ

B) -630 kJ/mol

Which measurement is expressed using 3 significant figures? A) 34.20 cm B) 0.0232 kg C) 10,550 m D) 68.003 g E) 222.0 km

B) 0.0232 kg

What is the mass, in lb, of a 225 g object? A) 0.4956 B) 0.496 C) 0.500 D) 0.49559 E) none of these

B) 0.496

How many millimeters are there in 0.010 km? A) 1.0 x 10^-8 B) 1.0 x 10^4 C) 0.010 D) 10 E) 1.0 x 10^-5

B) 1.0 x 10^4

Calculate the wavelength in meters of light absorbed by an electron in an atom of hydrogen as it moves from n = 3 to n = 6. a) 8.22 × 10-7 m b) 1.09 × 10-6 m c) 3.28 × 10-6 m d) 1.65 × 10-11 m e) 1.83 × 10-7 m

B) 1.09 x 10^-6 m

What is the average mass in kilograms of one atom of arsenic? A) 0.074922 kg B) 1.24 × 10-25 kg C) 1.24 × 10-22 kg D) 74.922 kg E) 5.48 × 10-23 kg

B) 1.24 x 10-25 kg

A 200.0 g sample of pure MgCl2 contains: A) 1.204 × 10^26 formula units MgCl2 B) 1.265 × 10^24 formula units MgCl2 C) 95.211 formula units MgCl2 D) 2.101 formula units MgCl2 E) 5.734 × 10^25 formula units MgCl2

B) 1.265 x 10^24 formula units MgCl2

If the density of lead is 11.34 g/cm3, how many atoms are in a piece of lead that is 2.00 cm wide, 1.00 m long, and 2.00 mm thick? A) 1.16 × 10^23 B) 1.32 × 10^24 C) 6.60 × 10^23 D) 1.16 × 10^22 E) 1.32 × 10^23

B) 1.32 x 10^24

A fish tank holds 40 gallon of water when full. What is the mass of this water in kilograms? A) 160 B) 150 C) 101 D) 9.5 E) 10.1

B) 150

Iron metal reacts with chlorine gas as follows: 2 Fe(s) + 3 Cl2(g) → 2 FeCl3(s) How many moles of FeCl3(s) are obtained when 4.6 mol of Cl2(g) reacts with excess Fe(s)? a) 1.5 mol b) 3.1 mol c) 4.6 mol d) 6.9 mol e) 2.3 mol

B) 3.1 mol

The following ratios of masses were obtained with a mass spectrometer: What is the mass of a 35/17 Cl atom in atomic mass units ? A) 13.95 u B) 34.97 u C) 36.36 u D) 35.00 u E) 35.45 u

B) 34.97 u

57.7 g Ni contains how many atoms? A) 6.13 × 1023 B) 5.90 × 1023 C) 3.47 × 1023 D) 0.983 E) 1.24 × 1024

B) 5.90 x 10^23

What is the mass percent of H2O in magnesium chloride hexahydrate? A) 8.86 % B) 53.2 % C) 26.6 % D) 64.4 % E) 10.7 %

B) 53.2 %

How many hydrogen atoms are there in 12.4 g of Al2(HPO4)3? A) 6.07 × 10^22 B) 6.55 × 10^22 C) 4.39 × 10^22 D) 1.32 × 10^23 E) 1.09 × 10^22

B) 6.55 x 10^22

The volume in L H2(g) (measured at 22 °C and 745 mmHg) required to react with 30.0 L CO(g) (measured at 0 °C and 760 mmHg) in the reaction below is: 3 CO(g) + 7 H2(g) → C3H8(g) + 3 H2O(l) a) 74.1 L b) 77.2 L c) 33.1 L d) 70.0 L e) 63.5 L

B) 77.2 L

A strip of electrolytically pure copper weighing 3.178 grams is strongly heated in a stream of oxygen until it is all converted to a black oxide. The resultant black powder weighs 3.978 g. What is the empirical formula of the oxide? A) CuO2 B) CuO C) CuO3 D) Cu2O E) Cu2O3

B) CuO

Which of the following processes does not represent a chemical change? A) reaction of sodium metal with water to give hydrogen gas and sodium hydroxide B) dissolving sugar in water C) souring of milk D) leaves changing color E) iron rusting

B) dissolving sugar in water

Which of the following does not represent a physical property? A) color B) flammability C) clarity D) melting point E) hardness

B) flammability

Consider the reaction: 4 NH3(g) + 5 O2(g) → 4 NO2(g) + 6 H2O(l) ΔH°f -46.19 0.00 90.37 -285.85 kJ/mol Compute ΔH° for this reaction. a) -622.62 kJ b) -241.67 kJ c) -1168.9 kJ d) -149.29 kJ e) 984.10 kJ

C) -1168.9 kJ

What is the concentration of Br- (aq) in a solution prepared by mixing 75.0 mL of 0.62 M iron(III) bromide with 75.0 mL of water? Assume volumes are additive. a) 0.31 M b) 1.9 M c) 0.93 M d) 0.62 M

C) 0.93 M

To produce ferrocene one requires 2.33 g of C5H5 (65.0 g/mol) for every 1.00 g of Fe used (55.9 g/mol). What is the value of x in the formula of ferrocene: Fe(C5H5)x ? A) 1 B) 5 C) 2 D) 3 E) 4

C) 2

When the equation Fe2(C2O4)3 → FeC2O4 + CO2 is balanced with the smallest integer coefficients, the coefficient of CO2 is: a) 3 b) 4 c) 2 d) 1 e) 5

C) 2

What is the energy in joules of the 656 nm spectral line of hydrogen. a) 1.45 × 10-48 J b) 1.30 × 10-22 J c) 3.03 × 10-19 J d) 3.03 × 10-28 J e) 4.35 × 10-31 J

C) 3.03 x 10^-19

A 10.0 g sample of bismuth tribromide, BiBr3, contains: A) 4.020 × 1022 total number of ions B) 0.322 mol BiBr3 C) 5.36 × 1022 total number of ions D) 1.34 × 1022 bromide ions E) 3.14 × 1022 formula units BiBr3

C) 5.36 x 10^22 total number of ions

What is the wavelength of a ball that is 25.0 g traveling at 90.0 miles per hour (40.2 m/s)? a) 1.07 × 10-30 m b) 2.42 × 10-11 m c) 6.59 × 10-34 m d) 6.59 × 10-37 m e) 4.12 × 10-37 m

C) 6.59 x 10^-34

The speed of light in a vacuum is approximately 3.0 x 10^8 m/s. What is the speed in miles per hour? A) 1.1 x 10^7 B) 3.0 x 10^8 C) 6.7 x 10^8 D) 4.5 x 10^5 E) 1.9 x 10^5

C) 6.7 x 10^8

An experiment calls for 22.6 g of bromine. What volume, in mL, should be used? A) 0.138 B) 22.6 C) 7.24 D) 70.5 E) none of these

C) 7.24

The substance NaOH in water solution is a: a) Weak Electrolyte b) Non-Electrolyte c) Strong Electrolyte d) Weak acid e) Weak Base

C) Strong Electrolyte

Which of the following is not an example of matter? A) water B) atoms C) light D) wood E) air

C) light

Which of the following is a heterogenous mixture? A) vinegar B) water C) root beer float D) sugar E) vegetable oil

C) root beer float

Which of the following pairs of atoms represent isotopes? A) 1H, 18O B) 14N, 14C C) 79Br, 35Cl D) 12C, 14C E) 77Se, 19F

D

Which of the following statements is true concerning the atomic masses of individual Cl atoms? A) All atoms have a mass of 17 u B) All atoms have a mass of 35.45 u C) Some of the atoms have a mass of 35.45 u D) None of the atoms have a mass of 35.45 u E) Most of the atoms have a mass of 35.45 u

D

Two solutions, 250.0 mL of 1.00 M CaCl2(aq) and 250.0 mL of 1.00 M K2CO3(aq), were added to a calorimeter with a heat capacity of 1.25 kJ/°C and the temperature decreased by 2.40 °C. Determine qrxn per mole of CaCO3(s) formed in the reaction. a) -12.0 kJ/mol b) +6.00 kJ/mol c) -6.00 kJ/mol d) +12.00 kJ/mol

D) +12.00 kJ/mol

Combine the reactions: P4(s) + 6 Cl2(g) → 4 PCl3(g) ΔH° = -1225.0 kJ PCl3(g) + 3 H2O(l) → H3PO3(aq) + 3 HCl(g) = - 853.5 kJ 2 H2(g) + O2(g) → 2 H2O(l) = - 571.5 kJ H2(g) + Cl2(g) → 2 HCl(g) = - 184.9 kJ to obtain the reaction: P4(s) + 6 H2(g) + 6 O2(g) → 4 H3PO3(aq) What is the value of ΔH° for this reaction? a) -9177.4 kJ b) 8605.9 kJ c) -2465.1 kJ d) -6958.6 kJ e) -2834.9 kJ

D) -6958.6 kJ

Which of the following represents a 1.00 M aqueous solution of glucose (C6H12O6)? a) 10.0 g glucose per 10.0 mL water b) 0.100 g glucose per mL solution c) 90.0 g glucose per 500 mL water d) 0.180 g glucose per mL solution e) 4.5 g glucose per 4.5 g water

D) 0.180 g glucose per mL solution

100.0 g of nickel at 150.0 °C was placed in 1.00 L of water at 25.0 °C. The final temperature of the nickel-water mixture was 26.3 °C. What is the specific heat of the nickel? a) 0.554 b) 0.130 c) 2.28 d) 0.439 e) 0.144

D) 0.439

What volume of 6.0 M sulfuric acid is required for the preparation of 500.0 mL of 0.30 M solution? a) 50 mL b) 30 mL c) 100 mL d) 25 mL e) 40 mL

D) 25 mL

Given the following reactions: Fe + Br2 → FeBr2 3 FeBr2 + Br2 → Fe3Br8 If each reaction gives 82.0% yield of desired product, what mass of Fe3Br8 is produced from 1.00 g Fe? a) 3.94 g b) 2.65 g c) 4.81 g d) 3.24 g e) 2.57 g

D) 3.24 g

In which of the following pairs is the oxidation number for the underlined element INCORRECT? a) MnO2 / 4 b) Cr2O3 / 3 c) SO3 2- / 4 d) ClO3- / 7

D) ClO3- / 7

Identify the reducing agent in the following reaction: 2 NO2(g) + 7 H2(g) → 2 NH3(g) + 4 H2O(g) a) H2O b) NH3 c) NO2 d)H2 e) there is no reducing agent

D) H2

Assuming ideal gas behavior, which of the following gases would have the lowest density at standard temperature and pressure? a) CO2 b) CF2Cl2 c) Kr d) N2 e) SF6

D) N2

Write the net ionic equation for the reaction of lead(II) nitrate and sodium iodide. a) Pb2+ + 2 NaI(aq) → PbI2(s) + 2 Na b) Pb2+ + 2 I- → Pb2+ + 2 I- c) Pb(NO3)2(aq) + 2 NaI(aq) → PbI2(s) + 2 NaNO3(aq) d) Pb2+ + 2 I- → PbI2(s) e) No reaction

D) Pb2+ + 2 I- → PbI2(s)

Calculate the mass, in grams, of 0.250 mol iron. A) 6.50 B) 11.2 C) 0.250 D) 55.9 E) 14.0

E) 14.0

What volume of 2.0 M HCl, in mL, is required to dissolve a 10.0 g piece of Zn? Zn(s) + 2 HCl(aq) → ZnCl2 (aq) + H2(g) a) 330 mL b) 76 mL c) 170 mL d) 310 mL e) 150 mL

E) 150 mL

Lead-204 has a relative abundance of 1.48%. What size block of lead (in cubic centimeters) will contain 8.34 × 1021 atoms of lead-204? The density of lead is 11.35 g/cm3. A) 194 B) 16.8 C) 0.253 D) 3.75 × 10-3 E) 17.1

E) 17.1

Which of the following reactions is an oxidation-reduction reaction? a) 2 CH3COOH(aq) + Ba(OH)2(aq) → Ba(CH3COO)2(aq) + 2 H2O(l) b) 2 NaHCO3(s) → Na2CO3(s) + H2O(g) + CO2(g) c) NH4HS(s) → NH3(g) + H2S(g) d) N2O4(g) → 2 NO2(g) e) 2 SO2(g) + O2(g) → 2 SO3(g)

E) 2 SO2(g) + O2(g) → 2 SO3(g)

Potassium superoxide (KO2) can simulate a plant-type action by consuming carbon dioxide gas and releasing oxygen gas. The other product is potassium carbonate. When the equation for this process is balanced, it shows that: a) moles of reactants equals moles of product b) 3 g of oxygen is produced per 2 g CO2 consumed c) moles of products exceed moles of reactants d) 3 mol oxygen is produced per mol KO2 consumed e) 2 mol KO2 is consumed per mol carbon dioxide

E) 2 mol KO2 is consumed per mol carbon dioxide

What is the sum of the coefficients when the following is balanced? PCl3(l) + Cl2(g) + P4O10(s) → POCl3(l) a) 10 b) 3 c) 18 d) 45 e) 23

E) 23

If the percent yield is 82.0%, how many grams of silicon are needed to make 105 g of chromium by the reaction: 3 Si (s) + 2 Cr203(s) → 3 SiO2 (s) + 4 Cr (l)? a) 92.2 g b) 13.0 g c) 34.9 g d) 42.5 g e) 51.9 g

E) 51.9 g

What is the percent yield if 185 grams of SiO2 are made from 328 g of Cr2O3 by the following equation? 3 Si(s) + 2 Cr2O3(s) → 3 SiO2(s) + 4 Cr(l) a) 56 % b) 105 % c) 70 % d) 142 % e) 95 %

E) 95 %

A 10.0 L container of unknown gas at 25.0 °C contains 87.1 g of gas at 12.5 atm. What gas is in the container? a) NO2 b) SO2 c) F2 d) C2H2 e) NH3

E) NH3

A closed system can exchange matter but not energy with the surroundings

False

A homogenous mixture has regions which are different in composition or phase

False

An atom with an even number of electrons is always diamagnetic

False

An intensive property is dependent of the amount of matter observed

False

An oxidizing agent is oxidized during a redox reaction

False

Energy is usually transferred from a cold object to a hot object

False

Ions ALWAYS adopt the electron configuration of a noble gas

False

Only metals in binary compounds use prefixes such as di- tri- tetra- etc.

False

The order of subshells of increasing energy in a multiple-electron atom is 4f, 5d, 6s, 6p

False

The periodic table contains more elements that are classified as non-metals than elements of any other type

False

The scientific method is used to make theories which can no longer be changed

False

The subscript (aq) indicates that the compound is dissolved in alcohol

False

The symbol "n" in the BOHR MODEL of atomic structure refers to the number of electrons in a shell

False

Two isotopes of the same element differ only in the number of protons found in the nucleus

False

Weak acids completely ionize in aqueous solution

False

Molarity is defined as moles of solute per L of solvent

False, Molarity=Moles Solute/L Solution

A molecular formula is the simplest formula possible

False, empirical formula

All atoms of a given element are identical

False, isotopes

The gram is the SI unit for mass

False, kg

A solid forming when two solutions are mixed is called a precipitate

True

An expansion of gas by a system means that the system does work

True

Atoms retain their identity during a chemical reaction

True

Enthalpy is an extensive property

True

In a balanced equation, the number of atoms of each element in the products must equal to the number of atoms each element in the reactants

True

Mercury is the only metal that is a liquid at room temperature

True

Oxidation never occurs alone

True

Soluble ionic compounds are strong electrolytes

True

The Bohr theory explains that an emission spectral line is due to an electron losing energy and changing orbits

True

The atomic mass for an atom is the weighted average of all the naturally occurring isotopes

True

The ionization energy is the energy change when a gaseous atom loses an electron

True

The number in front of formulas balanced equations are called stoichiometric coefficients

True

The solvent determines the state of the solution

True

Calculate the height of a column of liquid glycerol (d = 1.26 g/cm3), in meters, required to exert the same pressure as 4.91 m of water. a) 3.90 m b) 6.91 m c) 4.91 m d) 3.65 m e) 5.16 m

a) 3.90 m