Chapter 4
Carbon reservoirs ___
Exchange forms of carbon with each other Usually contain carbon in the form of one of its compounds
Radiative forcings
Factors that influence the balance of Earth's incoming and outgoing radiation May have either a cooling or a heating effect on Earth
An estimate of the amount of CO2 and other greenhouse gas emissions produced by an individual in a given time frame is referred to as that individual's carbon
Footprint
What is the mass of one atom of nitrogen (N)
For 1 atom of nitrogen, there is 1 atom ÷ 6.02x10^23= 1.661x10^-24. This corresponds to 1.661x10^-24x14.01= 2.3x10^-23
Calculate the mass% of O in a molecule of water, H2O
For one mole of H2O, the grams of O is 16.0 g. For one mole of the compound H2O, the total mass is 18.0 g. Therefore, the mass% of O in H2O is 16.0 g ÷ 18.0 g × 100% = 88.9%
Fuels formed by natural processes such as the decomposition of prehistoric organisms are called ___ fuels.
Fossil
Greenhouse gases have a ___ effect on a global warming than other anthropogenic forcings.
Greater
The car windows, like the ____________ of our atmosphere, trap the ____________ infrared radiation and makes the interior warmer than the outside.
Greenhouse gases Lower energy
Which of the following options correctly interpret the information provided by the balanced equation CH4+2O2= CO2+2H2O
1 molecule of CH4 reacts with 2 molecules of O2 15 mol of CH4 will produce 15 mol of CO2 when burned completely in O2 1 mole of CH4 produces 1 mole of CO2 when reacted with 2 moles of O2
Calculate the molar mass of CF2Cl2. In your answer, use 1 decimal place.
12.01 + 2(19.00) + 2(35.46) = 120.9 g/mol
The isotope Mg-25 isotope has ___ protons and ___ neutrons in its nucleus. Mg has an atomic number of 12
12; 13
One year, a herd of cattle released 4.1 metric tons of CH4 (methane) into the atmosphere. How many metric tons of carbon did this methane contain?
(12/16)*100%=75% carbon 4.1*(12/16)=3.1 metric tons C
Bond angle for tetrahedral molecule (such as CH4) is equal to
109.5
An element has two naturally-occurring isotopes. The mass numbers of these isotopes are 117 amu and 119 amu, with natural abundances of 85% and 15%, respectively. Calculate its average atomic mass. Report your answer to 1 decimal place.
17 amu × (85/100) = 99.45 amu 119 amu × (15/100) = 17.85 amu 99.45 + 17.85 = 117.3 amu
How many atoms are contained in 2.9 g of carbon? Round your answer to 2 significant figures.
2.9 g ÷ 12.01 g/mol = 0.2415 mol 0.2415 mol × 6.02 × 10^23 atoms/mol = 1.5 × 10^23 atoms
How much sulfur dioxide (SO2) can be produced by the combustion of 21 tons of sulfur (S)?
21 x (64/32)= 42 tons
Which statement correctly describes the procedure used to predict the ion formed by a main-group element?
A metal loses enough electrons to attain the same number as its nearest noble gas
For any element, the atomic mass recorded on the periodic table is not a whole number since it is an ___ of the masses of its naturally occurring isotopes
Average
The cars interior, like the Earths ____, absorbs ___ and ___ infrared radiation then emits ___ infrared radiation back out
B All C Some B Stratosphere
Describe the shape of a SO2 molecule.
Bent
2 bonding pairs, 2 lone pairs
Bent 104.5
Ozone is able to act as a greenhouse gas because its ____ shape allots it to vibrate in ways that involve ____ in overall charge distribution.
Bent; a change
A molecule will absorb IR radiation if it is capable of vibrational mode
D, A, C
The most electronegative element is
Fluorine
OH-
Hydroxide
Any gas that can absorb _____ radiation can act as a greenhouse gas.
Infrared
The central oxygen atom is H2O is surrounded by four electron pairs. The two lone pairs occupy more space than the bonding pairs, causing the bond angle in H2O to be ___ the ideal angle of 109.5
Less than
2 bonding pairs
Linear 180
What is the correct systematic name for the ionic compound Li3N?
Lithium nitride
Rank the following countries in order of increasing ecological footprint. Start with the country that has the lowest ecological footprint at the top of the list.
Mexico, China, France, US
The molar mass of any substance is the mass of 1 ___ of the particles of that substance
Mole
The charge of an ion with more electrons than its neutral atom is
Negative
No-3
Nitrate
NO-2
Nitrite
Vibrations of some molecules will absorb infrared radiation while others will not. Do the following vibrations absorb? Select Yes or No.
Nitrogen: no Dichlorodifluoromethane: yes Carbon dioxide no
PO3-4
Phosphate
A unit that contains two or more elements covalently bonded together but that has an overall charge is called an ___ ion. Many ___ compounds contain such units.
Polyatomic; ionic
The charge of an ion with fewer electrons than its neutral atom is
Positive
The process whereby a solid forms and separates from solution is called
Precipitation
What is the correct systematic name for the compound Na2CO3
Sodium carbonate
A ___ is a homogeneous mixtures of a solvent and one or more solutes
Solution
The component that is the most abundant in a solution is called the ___, whereas any dissolved substance is called a ___
Solvent; solute
Which of the following are three-dimensional representations of a molecule? Select all that apply.
Space filling model & wedge dash representation
SO2-4
Sulfate
SO2-3
Sulfite
Degasification is
The loss of a gas from a liquid solution
Which of the following statements correctly describe the carbon cycle?
The main atmospheric form of carbon is CO2 CO2 is generated by the combustion of fossil fuels.
Which of the following options correctly describe the isotope Cr-53, if the element Cr (chromium) has an atomic number of 24?
This isotope contains 29 neutrons in its nucleus The element contains 24 protons in its nucleus
Which of the following options correctly describe the electron groups & geometry of the molecule shown? CL-P-CL | CL
This molecule is trigonal pyramidal in shape. There are 4 electron groups around the central P atom
3 bonding pairs
Trigonal planar, 120
A certain combustion reaction generates 2.5 moles of carbon dioxide. How many grams does this represent? Report your number to one decimal place.
Using the atomic weights of C and O from the periodic table, first calculate the molar mass of CO2: 44.0 2.5*44=110
The car windows allow ____________ and infrared radiation to pass into the car. Similarly, our atmosphere allows ____________ infrared radiation and ____________ to pass through.
Visible light Higher energy Visible light
An estimate of the biologically productive space necessary to support a particular standard of living is called an
Ecological footprint
Which of the following correctly describe how Roman numerals are used in naming and writing chemical formulas? Select all that apply.
A Roman numeral is included for any metal that can form more than one monatomic cation The ion designated Fe(III) has a charge of +3
Which of the following options correctly describe how aerosols interact with radiation and affect Earth's temperature?
Aerosols promote cloud formation, allowing more solar radiation to be reflected. This has a cooling effect. Aerosols scatter incoming radiation efficiently, decreasing the amount of radiation available for greenhouse gases to absorb.
The proportion of incoming radiation that is reflected by a surface is called the ____. This quantity is a measure of the reflectivity of a surface.
Albedo
An ion with more electrons than its neutral atom is called a
Anion
An ______ solution is one in which water is the solvent
Aqueous
Isotopes are atoms of the same element that have the same ___ number but a different ___ number. This is because isotopes have the same number of protons but a different number of ___.
Atomic; mass; neutrons
Match each ecological footprint with the correct value, according to the estimates made in 2011 6.9 2.7 1.7
Average ecological footprint in the US Average ecological footprint in the world Maximum sustainable ecological footprint on Earth
Which of the following options correctly explain how carbon-14 levels can provide information about the source of atmospheric CO2?
CO2 produced by burning fossil fuels causes the carbon-14 concentration in the atmosphere to decrease CO2 produced by burning of fossil fuels contains virtually no carbon-14
Which of the following ion combinations will result in an ionic compound that has a balanced number of positive & negative charges?
Ca2+ & 2F Na+ & Br- 2Li+ & S2-
One system used in the United States to encourage reduction in CO2 emissions is the ___-and-____ system, which sets an upper limit for CO2 emissions for the year for a given company. A company may purchase extra allowances from a company that is under its limit for the year.
Cap; trade
The atomic mass of an element is the mass in grams of the same number of atoms found in exactly 12 g of ___-12
Carbon
The most abundant isotope of ___ is the internationally accepted standard for determining atomic mass.
Carbon
Atmospheric Lifetime
Carbon dioxide can be removed from the atmosphere by dissolution into the oceans Methane readily reacts with tropospheric free radicals
Atmospheric Concentration
Carbon dioxide concentrations are nearing 400 ppm
An ion with fewer electrons than its neutral atom is called an
Cation
When naming an ionic compound, the ___ is always named first. To name the anion, the root of the nonmetal name is added to the suffix ___.
Cation; -ide
Match each forcing with the effect is has on global temperatures on Earth. Increasing atmospheric CH4 Increasing cloud cover An example of a positive forcing is An example of a negative forcing is
Causes a warming effect Causes a cooling effect Increasing levels of greenhouse gases in the atmosphere Increasing levels of aerosols in the troposphere
Match each type of radiation to the effect it has on a molecule IR radiation UV radiation Microwave
Causes the molecule to vibrate Breaks bonds, causing the molecule to dissociate Causes the molecule to spin faster
Correctly order the steps required to determine the shape of a molecule, starting with the first step at the top of the list.
Determine the number of outer electrons associated with each atom in the molecule Arrange the outer electrons in pairs, ensuring that all atoms other than hydrogen obey the octet rule Determine the shape of the molecule by examining the position of the bonding & nonbonding electron pairs with respect to each other.
The most important greenhouse gas on Earth is carbon
Dioxide
The natural process by which Earth's atmospheric gases trap the infrared radiation radiated by Earth is called the ____ effect. This causes Earth's average surface temperature to be ____ than that predicted when considering the distance of the Earth from the Sun.
Greenhouse; higher
Which of the following options correctly describe the interaction of a molecule with IR radiation?
IR radiation can excite both bending and stretching vibrations. The wavelengths of IR radiation absorbed depends on the structure of the molecule IR radiation causes the bonds in a molecule to vibrate in various ways.
Which of the following options describe the correct format used to represent a chemical compound?
In the formula of an ionic compound the cation is always placed first The number of atoms/ions in the formula is indicated by a subscript
Match each solar body with the primary type of radiation it emits. Earth Sun
Infrared radiation Ultraviolet, visible & infrared
In an ___ compound electrons are transferred from one atom or group of atoms to another. Conversely, in an ___ compound electrons are shared.
Ionic; covalent
Which of the following statements correctly describe isotopes?
Isotopes have different numbers of neutrons Each elements atomic mass is a weighted average of the masses of the elements' isotopes
The chemistry of carbon-based compounds is called ___ chemistry
Organic
The most stable molecular arrangement is the one in which the ____ electron groups are as far apart as possible, to minimize electron-electron ____.
Outer; repulsion
Vibrations of some molecules will absorb infrared radiation while others will not. Do the following vibrations absorb? Select Yes or No.
Oxygen: no Carbon dioxide: yes Dichlorodifluoromethane: yes
Which of the following are considered possible effects of climate change?
Rise in sea levels An increase in the incidence of insect-borne diseases Changes in freshwater distribution
When sunlight hits a car, its windows absorb some radiation, such as UV- ____________ . In the atmosphere, ____________ of the UV- ____________ and ____________ of the UV- ____________ radiation is absorbed by reactions of oxygen and ozone in the ____________ .
Rocks and soil Visible light Higher energy Lower energy
Predict the molecular shape for each of these compounds. Remember to consider all of the outer electrons before you make your choice. Methane Ammonia Sulfur trioxide Water Ozone Carbon dioxide
Tetrahedral Trigonal pyramidal Trigonal planar Bent Bent Linear
4 bonding pairs
Tetrahedral, 109.5
What was the role of the IPCC (International Panel on Climate Change), established in 1988?
The IPCC was to assess both scientific and socioeconomic data relating to climate change
Suppose you have an Avogadro's number of carbon atoms. How many grams does this represent? Enter your answer to one decimal place.
The atomic weight listed in a periodic table for each element indicates how many grams are equivalent to one mole (an Avogadro number) of atoms. For carbon, the atomic weight is 12.0 g/mole; hence, one mole of carbon atoms has a mass of 12.0 g.
Which of the following options correctly describe a polyatomic ion? Select all that apply.
The atoms of a polyatomic ion are held together by covalent bonds The charge on a polyatomic ion belongs to the whole unit
Select the options that correctly reflect the mass rations and mass percentages of the elements in SO3
The mass percentage of O is 60% The mass ration of S is 0.400
Infrared Absorption Efficiency
The polarity of CFCs and the tetrahedral shape means that they absorb infrared at multiple wavelengths The bent shape & partial charges of nitrous oxide will lead to a large number of molecular vibrations that absorb IR
Which of the following factors influence the ability of a molecule to act as a greenhouse gas?
The shape of the molecule
Which of the following options correctly interpret the information given? Select all that apply. Molar mass of NO2=46.0 g/mol; atomic mass of nitrogen=14.0 g; atomic mass of oxygen=16.0 g.
There are 14.0g of nitrogen in every 46.0g of NO>2 The percentage oxygen in NO>2 is equal to 32.0/46.0 x100 The mass ratio of nitrogen is NO>2 is equal to .304
Which of the following correctly reflects Avogadro's Number
There are 6.02x10^23
This figure shows global emissions of C in metric tons per person per year for selected countries. Using this figure, how many metric tons of carbon dioxide are released per person in Italy per year?
There are approximately 44 metric tons of CO2 in every 12 metric tons of carbon, so the ratio of mass of CO2 to mass of carbon would be 3.67. (3.67/1)*2.3= 8.4 metric tons CO2
Which of the following options correctly describe the enhanced greenhouse effect?
This effect has resulted in an increase in average global temperatures on Earth. Atmospheric gases trap and return more than 80% of the heat radiated by Earth
3 bonding pairs, 1 lone pair
Trigonal pyramidal 107
Contrast weather & climate by matching each term to the correct definition.
Weather: describes events of relatively short duration, including daily high and low temperatures Climate: describes regional events recorded over longer periods
Ice core data shows that atmospheric CO2 levels ___
Were relatively constant from the beginning of the last millennium until around 1800
Match the symbols correctly to describe the uneven charge distribution in any polar covalent bond
δ+: marks the atom with the lower electronegativity δ-: marks the atom with the higher electronegativity
