exam 3 chem
The kinetic-molecular theory of gases assumes which of the following?
Gas molecules move constantly and in straight lines.
What substance would you add to NaHCO3(aq) to form a buffer solution?
H2CO3
Which of the following form a conjugate acid-base pair?
H2SO4 and HSO4-
A solution of toilet bowl cleaner has a pH of 9. The solution is
Weakly basic
What class of compounds often has a pleasant, fruity aroma?
esters
The intoxicating alcohol in "alcoholic" beverages is
ethanol
Using the IUPAC nomenclature system, name the following molecule.
heptane
Which of the following is an alkane?
heptane
Which of the following is an alkene?
heptene
Which of the following is an alkyne?
hexyne
The compound below is a(n) CH3CCH3--O
ketone.
Name the following hydrocarbons.
picture
A solution which has more H+ ions than OH- ions will have a pH equal to 7.
False
Compounds with the same number and kinds of atoms but with different structures are known as
isomers
Hydroiodic acid is classified as a strong acid in water. This means that it produces
100% of the maximum number of possible hydronium ions.
Lithium hydroxide is classified as a strong base in water. This means that it produces
100% of the maximum number of possible hydroxide ions.
An closed, rigid oxygen tank contains 4 L of oxygen at a pressure of 3 atm at 25 oC. If you place this oxygen tank in a cold room where the temperature is 4 oC, what will be the pressure inside the tank?
2.8atm
Glycerol is an alcohol with ________ hydroxyl groups
3
Hydrogen sulfate reacts with water to produce sulfate ions and hydronium ions: HSO4−+H2O⇌SO42−+H3O+ Identify the conjugate acid-base pairs.
Acid- HSO4- conjugate base- SO42- base- H2O conjugate acid- H3O+
Write the equation for the neutralization of aluminum carbonate by stomach acid (aqueous HCl). Express your answer as a chemical equation.
Al2(CO3)3+6HCl→2AlCl3+3CO2+3H2O
All of the following contribute to increasing indoor air pollution levels EXCEPT
All of the above contribute to increasing indoor air pollution. ~mold. gas kitchen stoves. improving insulation and sealing air leaks around windows and doors.
Complete the sentences related to an example of each type of interaction. Match words in the left column to the appropriate blanks in the sentences on the right. Make certain each sentence is complete before submitting your answer.
An example of ionic compound is sodium bromide ( N a B r ). An example of dipole-dipole forces is hydrogen chloride ( H C l ). An example of hydrogen bonding is ethyl alcohol ( C H 3 C H 2 O H ). An example of dispersion force is carbon tetrachloride ( C C l 4 ).
Which of the following is the correct balanced equation for the neutralization of barium hydroxide with sulfuric acid?
Ba(OH)2 + H2SO4 → BaSO4 + 2 H2O
The chemical formula of cyclopentane is
C5H10.
Which of the following is an aldehyde?
CH3CH2CH2CH2C=O---H
Diethyl ether is the most important of the ethers. It has the structure of
CH3CH2OCH2CH3.
Which substance causes fetal alcohol syndrome?
CH3CH2OH
Which of the following compounds is most likely to dissolve in water?
CH3OH
The formula of methanol is
CH3OH.
Which of the following alkanes will have the lowest boiling point?
CH4
What is the formula for calcium hydroxide?
Ca(OH)2
The cheapest base is ________.
CaO
What is the conjugate acid of HSO3-?
H2SO3
What base is formed by the addition of potassium oxide to water?
KOH
When added to water, which of the following would produce a base?
Li2O
Rank the following from most to least acidic. Rank from most to least acidic. To rank items as equivalent, overlap them.
Most to least H3O4=10-2 pH=2.5 pH=4 H3O4=10-5 pH=9
Which is a weak base in aqueous solution?
NH3
Which substance would exhibit intermolecular forces?
NH3
Write the equation that shows how ammonia acts as a Brønsted-Lowry base in water. Express your answer as a chemical equation.
NH3+H2O→NH4++OH−
The primary reaction in the formation of photochemical smog is
NO2 + sunlight → NO + O.
Which of the following ingredients would NOT be an active ingredient in an antacid?
NaBr
Identify the neutralization reactions. Drag the appropriate items to their respective bins.
Neutralization reaction other reaction
Which of the following is a hydroxide ion?
OH-
Which of the following is an example of a nonmetal oxide?
SO2
What is the conjugate base of HSO3-?
SO32-
Water is a liquid at room temperature while methane is a gas. Which statement compares the intermolecular forces in these molecules correctly?
The intermolecular forces in water are stronger than those in methane.
Which of the following properties are NOT a characteristic of ionic compounds?
They have low melting points.
Rainwater has a pH below 7 because raindrops absorb CO2CO2 which can react with water to form carbonic acid.
True
Select the processes that are impacted by greenhouse gases.
Variations in global temperature Increasing sea levels Melting or formation of glaciers and polar ice sheets
Citric acid is produced by oranges. When citric acid dissolves in water, it produces a relatively small number of hydronium ions. Citric acid is best described as a
Weak acid
Ammonia is classified as a weak base in water. This means that it produces
a relatively small fraction of the maximum number of possible hydroxide ions.
According to Arrhenius, an acid and a base will react to give
a salt plus water
Vinegar is a solution of ________ in water.
acetic acid
The compound below is commonly known as CH3-C-CH3=O
acetone
Sulfuric acid reacts with water to yield hydrogen sulfate ions and hydronium ions: H2SO4=H2O>HSO-4+H3O+ Identify the conjugate acid-base pairs.
acid-H2SO4 conjugate base-HSO-4 base-H2O conjugate acid-H3O+
Lemon juice has a sour taste and turns litmus to red. Lemon juice is
acidic
Acetylene is an
alkyne.
Which class of compounds contains only carbon, hydrogen, and nitrogen?
amines
Alkaloids, like morphine, caffeine, nicotine and cocaine, are heterocyclic
amines.
Amines are derivatives of
ammonia
Organic compounds that contain a benzene ring or possess certain properties similar to those of benzene are called ________ compounds.
aromatic
H2PO4−H2PO4− is the conjugate _____ of H3PO4H3PO4 and the conjugate _____ of PO3−4PO43−.
base/acid
All antacids are
bases
Many medicines have a bitter taste which manufacturers attempt to disguise. Many medicines are probably
bases
The most unique property of carbon is its ability to
bond to carbon.
Which of the following activities would NOT lower the amount of CO2 in the atmosphere?
building coal-fired power plants
What is the hydrogen ion concentration of a solution that has a pH of 7?
c(H+) =1×10−7
The presence of nitrogen dioxide in smog is most easily recognized by
color
Which of the following processes involves the removal of energy (heat)?
condensation
Choose the answer that correctly completes the statement: At 0∘C and 0.500 atm, 4.48 LNH3(g)
contains 6.02x10 22 molecules
The main ingredient in most antifreezes is
ethylene glycol.
One of the results of ozone pollution is
extensive damage to crops.
A buffer solution will become much more acidic when even a small amount of a strong acid is added.
false
A metal oxide will form an acid when it is dissolved in water.
false
Most alcohols are very safe to ingest.
false
One of the effects of increased levels of CO2 in the atmosphere is that the acidity of oceans will decrease.
false
The Arrhenius theory explains why ammonia, NH3, is basic, but the Bronsted-Lowry theory does not.
false
The concentration of air pollutants is almost always lower indoors than outdoors.
false
When an acid and a base react in a neutralization reaction, the products will be acidic.
false
pH is a measure of the acidity or basicity of an aqueous solution. Solutions with a pH less than 7 are acidic, solutions with a pH greater than 7 are basic or alkaline, and neutral solutions have a pH very close to 7. Arrange the following sources of water in decreasing order based on their pH values. Rank the items from highest pH to lowest pH.
highest>lowest ocean water pure water normal rainwater acid rainwater
Methanol has the formula CH3OH. What is the predominant intermolecular force between methanol molecules?
hydrogen bonds
What kind of intermolecular forces exists predominantly between the solute and solvent molecules in a solution of NaOH and water?
ion-dipole
A buffer
is made up of a weak base and its conjugate acid. is made up of a weak acid and its conjugate base. resists changes in pH when small amounts of a strong acid or a strong base are added. ~All of the above are true.
Which substance has the lowest pH?
lemon juice
Another name for NaOH is
lye
Most of the sulfuric acid produced in this country is used for
manufacturing fertilizer.
The compound CH3NH2 is called
methylamine.
Which substance has the highest pH?
milk of magnesia
A common name for hydrochloric acid is
muriatic acid.
Which of the following gases is most efficient at trapping atmospheric heat?
nitrogen trifluoride (NF3)
What is the IUPAC name for the following compound? CH3−CH2−CH2−CH2−CH2−CH2−CH2−CH2−CH3
nonane
Which one of the following is NOT a property of radon?
nonradioactive
Sodium bicarbonate is an old standby antacid. It is not recommended for persons suffering from high blood pressure because
of the presence of sodium ion.
What is the pH of an aqueous solution with [H3O+] = 4×10−13 M ?
pH=12.4
Compounds with a hydroxyl group attached directly to a benzene ring are called
phenols
A functional group is a specific set of atoms, arranged in a specific structure, that defines a particular class of organic compounds.
picture
Identify each property as that of alcohols, ethers, or both. Drag the appropriate items to their respective bins.
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Sort the processes based on whether they lead to an increase or a reduction of greenhouse gases in the atmosphere.
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The compound below is called CH3CH2-C-OH--O
propanoic acid.
Amino acids are the "building blocks" of
proteins
Methanol is an important solvent. It is also an important starting material for the synthesis of other molecules. Most methanol today is obtained from the
reaction of carbon monoxide and hydrogen at high temperature and pressure.
Sodium bicarbonate is the common name for what compound?
sodium hydrogen carbonate
Hyperacidity means
too much acid
A compound that contains a −NH2−NH2 group is an amine.
true
A conjugate acid-base pair form a buffer solution.
true
Acid rain slowly erodes marble statues because sulfuric acid will react with the calcium carbonate in marble.
true
Alkaloids, such as caffeine and cocaine, are basic compounds.
true
Antacids are basic compounds.
true
Most of the hydrocarbons found in the atmosphere come from natural sources.
true
Sulfuric acid is an excellent dehydrating agent and will remove water from the cells of skin.
true
The greenhouse effect occurs because greenhouse gases, such as carbon dioxide, absorb infrared energy and prevent heat from escaping into space.
true
Which is NOT a characteristic of bases?
turn litmus red
The first organic compound to be synthesized in a chemist's laboratory was
urea
What kind of particulate matter is often found inside homes?
wood smoke mold spores cigarette smoke
What percentage of hydrocarbons found in the atmosphere result from human activity?
15%
In the balanced chemical reaction for the neutralization of sodium hydroxide with sulfuric acid, H2SO4, the coefficient of sodium hydroxide is
2
A sample of gas at a temperature of 350 K has a volume of 4.00 L. The pressure remains constant. What is the volume of the gas at a temperature of 175 K?
2.00L
A bottle contains 40% ethanol. What is the proof of alcohol in this bottle?
80
Which pollutants are reduced in concentration by a catalytic converter?
Nitrogen oxide (NO), carbon monoxide (CO) and hydrocarbons are reduced by catalytic converters
Which of the following compounds is a phenol?
OH-Br
By definition, acid rain has a pH
below 5.6.
In organic chemistry, compounds are generally classified by
functional group.
Using the information in the introduction, sort the following chemicals based on whether they are the main contributors to the pH for normal rainwater, acid rain, or ocean water. Drag each item to the appropriate bin.
natural rainwater~CO2,H2CO3 Acid rain~SO2,H2SO4,SO3 natural ocean water~CaCO3
Matter is more likely to exist in the ________ state as the pressure is increased.
solid
Rank the following types of interactions between the particles of a substance in the liquid and solid states from strongest to weakest. Rank from strongest to weakest. To rank items as equivalent, overlap them.
strongest>weakest ionic bonds hydrogen bonds dipole-dipole forces dispersion forces
The process by which a solid is converted to a gas is called
sublimation.
The two principal sources of acid rain are ________ emissions from power plants and ________ emissions from automobiles and power plants.
sulfur dioxide, nitrogen monoxide
The World Health Organization (WHO) rates which pollutant the worst?
sulfur oxides
Which is NOT a characteristic of acids?
taste bitter
The formula for hexane is
C 6 H 14 .
A gas is enclosed in a cylinder fitted with a piston. The volume of the gas is 2.00 L at 1.00 atm pressure. The piston is moved to change the volume to 6.00 L. Which of the following is a reasonable value for the pressure of the gas at the new volume?
0.333 atm
