Chem Final Exam

A chemical reaction accompanied by a release of energy is called a/an _____ reaction A. endothermic B. catalyzed C. exothermic D. fast

C

A student wants to prepare exactly 500mL of a 0.500 M aqueous potassium hydroxide solution. What mass of potassium hydroxide (molar mass=56.10g/mol) must the student dissolve in the 250 mL of solution? A. 56.1 g B. 28.1 g C. 14.0 g D. 7.01 g

C

Both the Clinton and the Bush administrations have been unwilling to sign the Kyoto Protocol. What has been their primary objection to the treaty? A. The target emissions levels are not sufficiently low to affect the greenhouse effect B. The treaty does not include a provision for trading emission allowance C. Developing countries are not required to control greenhouse gas emissions D. Enforcement of the treaty will be impossible

C

Combustion of propane C3H8. The bond energies are C-H 416 kJ, C-C 356 kJ, O-O 498 kJ, C-O 803 kJ, H-O 467 kJ. Which is the amount of energy gained on making all the bonds in carbon dioxide and water according to the equation? A. -4277 kJ/mol B. -1270 kJ/mol C. -8554 kJ/mol D. -2540 kJ/mol

C

Consider the complete combustion of propane, C3H8. The bond energies are: C-H 416 kJ/mol, C-C 356 kJ/mol, O-O 498 kJ/mol, C-O 803 kJ/mol, H-O 467 kJ/mol. Which is the total amount of energy required to break all of the bonds in propane? A. 712 kJ/mol B. 3328 kJ/mol C. 4040 kJ/mol D. 4396 kJ/mol

C

Determine the molar mass for fluoxetine C16H16F3NO A. 279.3 g/mol B. 281.3 g/mol C. 295.3 g/mol D. 297.1 g/mol

C

Evaluate the ration MH+ (pH 2)/MH+ (pH 4) A. 0.0001 B. 0.001 C. 100 D. 10,000

C

Find the molar mass of ethanol, C2H6O A. 29.02 g/mol B. 45.06 g/mol C. 46.07 g/mol D. 110.0 g/mol

C

Generally, the water that has the least harmful contaminants is: A. water from the oceans B. surface water from lakes C. groundwater from aquifers D. surface water from rivers

C

If acids are compounds that release protons H+, how is that SOx and NOx cause acid rain? A. They react with hydrogen gas in the atmosphere to produce acids B. There is not sufficient evidence to indicate that these compounds actually do cause acid rain C. They react with water to form acids D. They react with ammonia to form acids

C

If the lead concentration in water is 1ppm then we should be able to recover 1mg of lead from ___L of water A. 0.01 B. 0.1 C. 1 D. 10

C

In an exothermic chemical reaction A. the mass of the products is greater than the mass of the reactants B. the mass of the products is less than the mass of the reactants C. heat is released as the reaction proceeds D. heat is absorbed as the reaction proceeds

C

In which example is the entropy of the initial state greater than the entropy of the final state? A. a building collapses during an earthquake B. a lump of sugar dissolves in a cup of warm water C. Liquid water freezes into ice D. liquid water evaporates

C

Neither N2 nor O2 are greenhouse gases because A. infrared radiation causes their bonds to break B. their atmospheric concentrations are not changed by human activity C. their overall electric charge distribution does not change when they vibrate D. N2 and O2 react with one another, producing N2O2 when exposed to infrared radiation

C

Octane (C8H18) is one of the principal components of gasoline. How many moles of CO2 are produced during the combustion of 3.0 mol of octane? Unbalanced equation: C8H18 + O2 -> CO2 + H2O A. 3.0 B 8.0 C. 24 D. 26

C

One of the functions of an automobile catalytic converter contributes to the battle against acid rain. Which reaction represents this function as carried out by a catalytic converter? A. HNO2 + NaOH -> H2O + NaNO2 B. NO2 + H2O -> HO+ + HNO2- C. 2 NO -> N2 + O2 D. HNO3 + NaOH -> H2O + NaNO3

C

The energy needed to initiate a chemical reaction is called the A. heat of combustion B. bond energy C. activation energy D. renewable energy

C

The energy stored in the chemical bonds of fossil fuels is a form of ____ energy. A. electrical B. mechanical C. potential D. kinetic

C

The formula for a sulfate ion is SO42-. What is the formula of aluminum sulfate? A. Al3(SO4)3 B. Al2SO4 C. Al2(SO4)3 D. AlSO4

C

What is an aquifer? A. a holding tank for disinfected water at the municipal water works B. a water purification system developed by the Romans C. a large pool of water trapped in sand and gravel below the surface of the earth D. a solution in which water is solven

C

What is the molarity of sodium chloride in a solution containing 0.50 mol of sodium chloride in 500mL of water? A. 0.25M B. 0.50M C.1.0M D.5.0M

C

What substance has the highest pH? A. orange juice B. rain C. a sulfuric acid solution D. a lye solution

C

Which chemical equation shoes the dissociation of 2 protons from trihydrogen phosphate? A. H3PO4 -> 2H+ + HPO4 2- B. H3PO4 -> H2 2+ + PO4 2- C. H3PO4 -> 2H+ + HPO4 2- D. H3PO4 -> H3 3+ + PO4 3-

C

Which chemical equation shows the dissociation of calcium hydroxide? A. CaOH -> Ca2+ + OH2- B. Ca(OH)3 -> Ca3+ + 3OH- C. Ca(OH)2 -> Ca2+ + 2OH- D. Ca(OH)2 -> Ca2+ + H2O + O2-

C

Which explanation accounts for the fact that, on average, cloudy nights are warmer than clear nights? A. H2O does not absorb infrared energy B. Clouds reflect light incoming from the moon C. Clouds are composed of water vapor and H2O is a strong greenhouse gas D. Clouds have a high concentration of carbon dioxide from fossil fuel combustion

C

Which nitrogen containing substance is generally unreactive? A. NO B. NaNO2 C. N2 D. NH3

C

Which shows the Lewis structure of water with the correct partial charges and nonbonding electrons? A. Just negative on the Hs with two nonbonding electrons B. Positive on the O, negative on the Hs with four nonbonding electrons C. Negative on the O, positive on the Hs, four nonbonding electrons D. Negative on the O, positive on the Hs, two nonbonding electrons

C

Which substance has the lowest pH? A. orange juice B. rain C. a sulfuric acid solution D. a lye solution

C

Which substances are regulated by the Kyoto Protocol? i. argon ii. carbon dioxide iii. nitrogen iv. methane v. sulfur hexaflouride A. i, ii, and iii only B. i and iii only C. ii, iv, and v only D. ii and v only

C

"Hard" water in parts of the Midwest may have a calcium ion concentration as high as 400ppm. What is this calcium ion concentration when expressed as a percentage? A. 40% B. 4% C. 0.4% D. 0.04%

D

A 0.25 M aqueous solution of potassium chloride KCl is tested for conductivity. What do you predict will happen? A. The light bulb will shine brightly. KCl is highly ionized in aqueous solutions B. The bulb will not light up. KCl is a nonelectrolyte C. The light bulb will shine dimly. KCl is only partially ionized in aqueous solutions D. The light bulb will shine brightly. KCl is highly ionized in aqueous solutions

D

A calorie is defined as exactly 4.184 J. Therefore, 1.000 kcal is exactly: A. 41.84 J B. 418.4 J C. 1000 J D. 4184 J

D

A proton released by an acid in aqueous solution quickly reacts with water to form a hydronium ion. What product is formed when a proton reacts with ammonia (NH3)? A. NH3+ B. NH4 C. NH2- D. NH4+

D

A student wants to prepare exactly 250mL of a 0.500 M aqueous potassium hydroxide solution. What mass of potassium hydroxide (molar mass=56.10 g/mol) must the student dissolve in the 250mL of solution? A. 56.1g B. 28.1g C.14.0g D.7.01g

D

Coal switching refers to the practice of: A. converting oil or natural gas power plants to coal because coal is cheaper B. pulverizing coal in order to make it burn more efficiently C. converting coal power plants to oil or natural gas to reduce SOx emissions D. using coal with lower sulfur content to reduce SOx emissions

D

Identify the possible consequences of global warming i. a rise in sea level ii. an increase in avg. relative humidity iii. an increase in forest growth in the northern hemisphere iv. a weakening of ocean currents A. i and iii only B. i and iv only C. i, ii, and iv only D. i, ii, iii, and iv

D

If the mercury concentration in water is 1ppm, then we should be able to recover 10mg of lead from ____ L of water. A. 0.01 B. 0.1 C. 1 D. 10

D

In which example is the entropy of the initial state lower than the entropy of the final state? A. a raw egg heated at 100 C in boiling water becomes hard boiled B. librarians put library books back onto the shelves at the end of the day C. soldiers are called to attention when the general enters the room D. a pot of water boils to produce water vapor at 100 C

D

The carbon cycle refers to: A. mechanism by which carbon dioxide causes global warming B. frequency of light energy that affects the rotational energy of carbon dioxide C. oxidation of glucose to form carbon dioxide and water D. movement of carbon through living organisms, the atmosphere, the sea, and the earth

D

The greenhouse effect refers to the return of approx. _____ percent of heat radiated by earth A. 40 B. 50 C. 60 D. 80

D

The heat combustion of ethane, C2H6, is 1560 kJ/mol. What is the heat of combustion of ethane, in kJ per gram? A. 9.39 x 10^26 kJ/g B. 4.69 x 10^4 kJ/g C. 195 kJ/g D. 51.9 kJ/g

D

The heat of combustion of methane, CH4, is 50.1 kJ/g. How much heat would be generated if 1.00 mol of methane undergoes complete combustion? A. 0.32 kJ B. 3.12 kJ C. 601 kJ D. 804 kJ

D

The history of avg. global temp for the last 160,000 years is derived from isotopic analysis of ice layers in Antartica. Scientists study the ____ ratio in ____ A. 16O/18O; O2 B. 12C/14C; CO2 C. 14C/12C; CH4 D. 1H/2H; H2O

D

The primary product of the combustion of sulfur is: A. H2S B. H2SO4 C. H2SO3 D. SO2

D

The recommended daily requirement of calcium is 1000mg. Tap water in a Midwestern city contains aprox. 150mg CA/L. A person living in the city who drinks two liters of water in one day would receive _____ percent of his RDA of calcium. A. 15 B. 3 C. 7.5 D. 30

D

Water has one of the highest specific heats of any known liquid. This means that the temperature of a water sample ____ with the input of a ____ amount of energy. A. increases only slightly; large B. decreases greatly; small C. decreases only slightly; large D. increases only slightly; large

D

What atmospheric component is responsible for the natural acidity of rain? A. nitrogen B. ozone C. oxygen D. carbon dioxide

D

What is the correct name for (NH4)2CO3? A. biammonium carbonate B. ammonium bicarbonate C. ammonium carboxide D. ammonium carbonate

D

What is the effect of infrared energy on matter? A. it excites bonding electrons B. it increases molecular rotation C. it breaks chemical bonds D. It increases the vibration of chemical bonds

D

Which anthropogenic pollutants are implicated in the formation of most acidic precipitation? A. carbon oxides B. phosphoric acid and hydrochlroic acid C. ozone and carbon monoxide D. nitrogen oxides and sulfur oxides

D

Which concentration is consistent with a basic solution? A. MH+ = 3.2x10^-3 M B. MOH- = 3.6x10^-9 M C. MH+ = 9.7x10^-4 M D. MOH- = 3.4x10^-3 M

D

Which correctly describes groundwater? A. any water found above ground in lakes and rivers; usually needs treatment to remove harmful contaminants B. any water found above ground in lakes and rivers; usually free of harmful contaminants C. any water taken from aquifers; usually needs treatment to remove harmful contaminants D. any water taken from aquifers; usually free from harmful contaminants

D

Which corresponds to the composition of the ion typically formed by magnesium? A. P=12 E=14 NC=2+ B. P=12 E=14 NC=2- C. P=12 E=10 NC=2- D. P=12 E=10 NC=2+

D

Which is a fossil fuel? A. wood B. uranium C. ethanol D. natural gas

D

Which practices might be described as carbon sequestration? i. planting trees ii. deforestation iii. pumping carbon dioxide deep into the ocean iv. increasing combustion of fossil fuels A. i and ii only B. ii and iii only C. iii and iv only D. i and iii only

D

Which reaction represents an acid base neutralization reaction? A. HNO2 + H2O -> H3O+ + NO2- B. NaOH + H2o -> H3O+ + NaO- C. Ba(OH)2 + 2LiCl -> BaCl2 + 2LiOH D. Be(OH)2 + H2SO4 -> BeSO4 + 2 H2O

D

A 0.25 M solution of the sugar sucrose in water is tested for conductivity using the apparatus shown. What do you predict will happen? A. the bulb will not light up. Sucrose is in the molecular form in aqueous solutions B. the bulb will not light up. Sucrose is an electrolyte, but not very soluble in aqueous solutions C. the light bulb will shine brightly. Sucrose is highly ionized in aqueous solutions D. the light bulb will shine dimly. Sucrose is only partially ionized in aqueous solutions.

A

A 4L sample of water contains 80mcg of lead. What is this lead concentration in ppb? A. 20 B. 80 C. 320 D. 500

A

Bases produce which ions in aqueous solution? A. OH- B. NO2- C. Cl- D. SO3-

A

Determine the shape or geometry of CH4 A. tetrahedral B. trigonal pyramid C. bent D. trigonal planar

A

Electronegativity: A. is a relative measure of an atom's attraction for electrons it shares in a covalent bond B. is the total negative charge on a polyatomic anion C. is the same for all of the elements in a family or group D. decreases from left to right across a period on the periodic table

A

Ethanol (C2H6O) is a common intoxicant and fuel produced from the fermentation of various grains. How many moles of ethanol are represented by 50.0 g of ethanol? A. 1.09 mol B. 46.1 mol C. 9.00 mol D. 109 mol

A

Evaluate the ration MH+ (pH 3)/MH+ (pH7) A. 10,000 B. 0.0001 C. 0.01 D. 0.429

A

How many moles of sodium chloride are there in 250mL of a 1.20 M sodium chloride solution? A. 0.30 B. 0.60 C. 1.2 D. 2.4

A

In the petroleum industry, what does a refinery do? A. it separates crude oil into fractions consisting of compounds with similar boiling points B. it separates crude oil from the coal with which it is almost always found C. it mixes natural gas or coal with crude oil in order to remove the impurities from the crude oil D. it produces the machinery by which crude oil is removed from the ground

A

Predict the products of this reaction: KOH + HNO3 -> A. KNO3 + H2O B. KNO2 + H202 C. KH + HNO4 D. KO4 + H2N

A

The Industrial Revolution is a key point in earth's atmospheric history because A. prior to that time large deposits of petroleum and coal were not being used as energy sources B. the first atmospheric studies were conducted at the time C. spectrometers that could measure molecular response to infrared radiation were developed at the time D. the first aircraft that could be used to collect atmospheric samples were developed at the time

A

The acid neutralizing capacity of a lake or stream most often derives from the presence of ____ in the surrounding soil or rock A. CaCO3 B. HNO3 C. NaCl D. Sr(OH)2

A

The degree of randomness in position or energy is called the A. entropy B. activation energy C. heat of combustion D. potential energy

A

The formation of nitric oxide (NO) from oxygen and nitrogen is ordinarily a very slow process. What accounts for its more rapid formation in automobile exhaust? A. the extreme conditions involved in gasoline combustion B. the presence of nitrogen compounds in gasoline C. catalysts present in fuel that facilitate its formation D. well designed catalytic converters

A

The hydronium ion concentration in a solution with pH 10 is _____ than the hydronium ion concentration in a solution with a pH 13 A. 1,000 times greater B. 3 times greater C. 1,000 times less D. 100 times less

A

The hydronium ion concentration in a solution with pH 4 is ___ than the hydronium ion concentration in a solution with pH 8. A. 1,000 greater B. 3 times greater C. 1,000 times less D. 100 times less

A

What is the formula of the ionic compound formed from magnesium and chlorine? A. MgCl2 B. Mg2Cl2 C. MgCl D. Mg2Cl

A

What is the molarity of sodium chloride in a solution containing 0.10 mol of sodium chloride in 400 mL of water? A. 0.25 M B. 0.50 M C. 1.0 M D. 5.0 M

A

What is the source of nitrogen in the NOx emitted from fossil fuel combustion? A. the atmosphere B. coal C. natural gas D. oil

A

Where it most of the carbon on earth stored? A. in the form of fossil fuels and carbonate minerals and rocks B. in the forests and soil C. in surface water D. in the atmosphere

A

Which chemical equation shows the dissociation of magnesium hydroxide? A. Mg(OH)2 -> Mg2+ + 2OH- B. MgOH -> Mg2+ + OH2- C. Mg(OH)3 -> Mg3+ + 3OH- D. Mg(OH)2 -> Mg2+ + H2O + O2-

A

Which concentration is consistent with an acedic solution? A. MH+ = 3.2x10^-3 M B. MOH- = 3.6x10^-6 M C. MH+ = 9.7x10^-9 M D. MOH- = 3.4x10^-3 M

A

Which covalent bond is the most polar? A. H-O B. H-H C. H-N D. H-S

A

Which international agreement attempted to reduce greenhouse gas emissions? A. Kyoto Protocol B. Montreal Protocol C. Oslo Accords D. Nuremburg Treaty

A

Which reaction accounts for the fact that the pH of rain is naturally slightly acidic? A. CO2 + H2O -> H+ + HCO3- B. SO3 + H2O -> 2 H+ + SO4 2- C. Ca2+ + CO2 + H2O -> CaCO3 + 2 H+ D. NO2 + H2O -> 2 H+ + NO3-

A

Which reaction most accurately represents the dissociation of nitrous acid (HNO2) in water? A. HNO2 + H2O -> H3O+ + NO2- B. HNO2 + H2O -> H3O2+ + NO- C. HNO2 + H2O -> HN + HO+ + HO2- D. HNO2 + H2O -> H30+ + N +O2-

A

Although greenhouse gases likely account for the problem of global warming, they are also responsible for making earth habitable. What would be the temperature on earth in the absence of the effects of carbon dioxide and water? A. -270 C B. -18 C C. 15 C D. 450 C

B

Determine the shape or geometry of NH3 A. tetrahedral B. trigonal pyramidal C. bent D. trigonal planar

B

How many moles of potassium chloride are there in 500mL of a 1.20 M sodium chloride solution? A. 0.30 B. 0.60 C. 1.2 D. 2.4

B

Hydrogen gas is a promising alternative to fossil fuels. How many moles are present in 1.0kg of hydrogen gas? A. 3.0 x 10^-23 B. 496 C. 1000 D. 6.0 x 10^26

B

Identify the singe most effective strategy to reduce carbon dioxide emissions A. use methane rather than gasoline for fuel in cars and trucks B. develop alternate energy sources that do not reply on fossil fuels C. use wood as a home heating fuel D. convert all vehicles to diesel fuel

B

In a typical power plant, the combustion of fuel is used to boil water. The steam then causes a turbine to spin. At this stage, the potential energy of the fuel has been transformed into _____ energy of the spinning turbine. A. chemical B. mechanical C. electrical D. potential

B

Petroleum is a complex mixture of thousands of substances, the majority of which are: A. carbohydrates B. hydrocarbons C. natural gases D. proteins

B

Sulfur oxides have been implicated as important contributors to acid rain. What is the principal anthropogenic source of these compounds? A. transportation B. coal fired power plants C. lightning D. volcanoes

B

The ability of a molecule to absorb infrared radiation is measured with IR spectrometers, which report the frequency of light absorbed in units of cm-1. Which explanation best describes this unit? A. the distance traveled by light of a specific frequency in 1 second B. the number of wavelengths in 1 cm for a specific frequency of light C. the wavelength of a specific frequency of light D.the speed of a specific frequency of ligth

B

The drawing shows two water molecules. Which statement is correct? (Drawing shows a solid line between O and H and then a dotted kine between H and O) A. a: covalent bond b: hydrogen bond; B is stronger B. a:covalent bond b: hydrogen bond; A is stronger C. a: hydrogen bond b: covalent bond; A is stronger D. a: hydrogen bond b: covalent bond; B is stronger

B

The fact that carbon is less electronegative than nitrogen means that in a C N bond, the: A. shared electrons are closer to the C atom than to the N atom B. shared electrons are closer to the N atom than to the C atom C. C atom takes the electrons from the N atom forming C- and N+ D. N atom takes the electrons from the C atom forming C+ and N-

B

The pH of lemon juice is approx. 2.40. At this pH, the hydronium ion concentration is closest to which concentration? A. 2.5x10^-12 M B. 4.0x10^-3 M C. 0.38 M D. 5.6x10^-4 M

B

The pH of rain water falling through an unpolluted atmosphere is closest to: A. 4.7 B. 5. 4 C. 7.0 D. 8.7

B

What evidence indicates that the rising atmospheric CO2 levels are caused by the combustion of fossil fuels? A. the 14C/12C ratio in atmospheric CO2 is unusually low B. the 18O/16O ratio in atmospheric CO2 is the same as in atmospheric oxygen C. both the average global temperature and the atmospheric CO2 level have risen D. The level of atmospheric moisture has increased

B

What is the coefficient for oxygen in the balanced chemical equation for the combustion of heptane? C7H6 + O2 -> CO2 + H2O A. 7 B. 11 C. 8 D. 1

B

Which atmospheric component does not contribute to global warming? A. H2O B. N2 C. CO2 D. O3

B

Which best symbolizes the hydrogen bonding between two water molecules? A. H-H B. O-H C. OO-OO D. O-O

B

Which corresponds to the composition of the ion typically formed by fluorine? A. P=9 E=10 NC=1+ B. P=9 E=10 NC=1- C. P=9 E=8 NC=1- D. P=9 E=8 NC=1+

B