CHEM1010 Chapter 4

In order for a molecule to absorb IR radiation, the energy of the IR radiation must ____.

match one of the vibrational energy modes of the molecule

In the compound MgO, the Mg ion has a charge of ____, while the O ion has a charge of ____.

+2; -2

The most abundant isotope of ____ is the internationally accepted standard for determining atomic mass.

carbon

All atomic masses are determined relative to the mass of an atom of ____.

carbon-12

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

In order for a molecule to absorb IR radiation, the energy of the IR radiation must ___.

match one of the vibrational energy modes of the molecule.

Which chlorofluorocarbon has the greatest carbon mass ratio?

C2Cl2F4

A chlorofluorocarbon has a chemical formula of CF2Cl2 and a molar mass of 120.9 g/mol. The atomic mass of carbon is 12.0 g/mol. The mass ratio of carbon in this compound is correctly expressed as ____.

(12.0g C)/(120.9g CF2 Cl2)

Which of the following options correctly describe variations in solar irradiance and its effect on Earth's climate?

--- Seasonal variations in sunlight intensity affect local temperatures significantly. --- Changes in the Earth's orbit can affect the amount of solar radiation that reaches the Earth.

Which of the following are considered possible effects of climate change?

-An increase in the incidence of insect-borne diseases -Changes in freshwater distribution -Rise in sea levels

Which of the following options correctly describe how to name an ionic compound? Select all that apply.

... the cation is named first and the anion second ... when naming the anionic portion of the ionic compound, the element name is changed to end in -ide

Consider the formula for the ionic compound Na2O. Which of the following statements correctly interpret this formula? Select all that apply.

... the compound contains 2 Na+ ions for every O2- ion ... the cation in this compound is Na+

Which of the following options correctly describe the greenhouse effect? Select all that apply.

... the greenhouse effect causes the average temperature on Earth to be higher than predicted when considering its distance from the Sun ... atmospheric gases on Earth trap about 80% of the infrared radiation produced by the Earth, warming the planet ... the greenhouse effect is a natural process

Which of the following correctly describe how Roman numerals are used in naming and writing chemical formulas? Select all that apply.

... the ion designated Fe(III) has a charge of +3 ... a Roman numeral is included for any metal that can form more than one monatomic cation

Select the options that correctly reflect the mass ratios and mass percentages of the elements in SO3.

... the mass ratio of S is 0.400 ... the mass percentage of O is 60.0%

Which of the following statements correctly describe molar mass? Select all that apply.

... the molar mass of oxygen is 16.00 g/mol which means that 1 mole of oxygen atoms has a mass of 16.00 g ... the periodic table can be used to calculate the molar mass of any substance ... the molar mass of a molecular substance is the mass per mole of its molecules

Which of the following statements correctly describe the mole? Select all that apply.

... the number of particles in a mole is called Avogadro's number ... one mole of any substance contains 6.02 x 10^23 particles

Which of the following options correctly differentiate between weather and climate? Select all that apply.

... the term "climate" refers to regional trends in temperatures, rainfall, etc ... weather includes daily variations in temperature and rainfall at a single location ... the term "weather" refers to events that have a relatively short duration

Correctly order the steps required to determine the shape of a molecule, starting with the first step at the top of the list.

1- determine the number of outer electrons associated with each atom in the molecule. 2- Arrange the outer electrons in pairs, ensuring that all atoms other than hydrogen obey the octet rule. 3- Determine the share of the molecule by examining the position of the boding and nonbonding electron pairs with respect to each other.

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.

1- mexico 2- china 3-france 4-United states

The bond angle for a tetrahedral molecule (such as CH4) is equal to ____.

109.5 degrees

Sunspots typically occur about every _____.

11 years

Match each ecological footprint with the correct value, according to the estimates made in 2011 6.8 2.7 1.7

6.8- avg ecological footprint in the us 2.7- avg ecological footprint in the world 1.7- maximum sustainable ecological footprint on earth.

Which of the following are three-dimensional representations of a molecule? Select all that apply.

A: In the plane of the page B: In front of the plane of the page C: Behind the plane of the page

What is meant by the term "carbon footprint" when applied to an individual?

An estimate of the amount of CO2 and other greenhouse gas emissions produced by the individual in a given time frame

Which greenhouse gas listed has the highest molar gas?

CF2Cl2

Which greenhouse gas listed has the highest molar mass?

CF2Cl2

Which carbon and oxygen containing compound has a molar mass of 44.01 g?

CO2

Which gas is central to the discussion of global climate change?

CO2

Which of the following elements will form a cation? Select all that apply.

Ca Rb

An ecological footprint estimates the biologically productive space required to support a particular lifestyle. Which of the following are included in this estimate? Select all that apply.

Fresh water Land Sea surface

Any gas that can absorb _____ radiation can act as a greenhouse gas.

IR or infrared

Which type of radiation is absorbed by all greenhouse gases?

IR radiation

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.

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

Which statement correctly describes the procedure used to predict the ion formed by an element? (Excludes groups 3-12)

a metal loses enough electrons to attain the same number as its nearest noble gas

Match each type of electron pair to the correct designation.

a-lone pair b-bonding electron pair

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

For any element, the atomic mass recorded on the periodic table is not a whole number since it is a(n) ____ of the masses of its naturally occurring isotopes.

average or weighted average

Both Venus and Earth have higher average surface temperatures than expected because ____.

both planets have atmospheres that trap radiation

Which human activity has the GREATEST net effect on atmospheric CO2 levels?

burning fossil fuels

The atomic mass of an element is the mass in grams of the same number of atoms found in exactly 12g of ___ -12.

c or carbon

The most important greenhouse gas on Earth is carbon ____.

dioxide

Which of the following options correctly describes the underlying principle used to determine molecular shape from a Lewis structure?

each group of outer electrons around a central atom is located as far from the others as possible

An estimate of the biologically productive space necessary to support a particular standard of living is called a(n) _____.

ecological footprint

The most electronegative element is _______.

flourine

The most electronegative element is ____.

fluorine

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 difference between the terms global warming and climate change?

global warming is one aspect of climate change

Greenhouse gases have a _____ effect on global warming than other anthropogenic forcings.

greater

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

Small changes in the average global temperatures are expected to have a(n) ____ impact on our climate.

huge

In a(n) ____ compound electrons are transferred from one atom or group of atoms to another. Conversely, in a(n) ____ compound electrons are shared.

ionic; covalent

The central oxygen atom in 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 degrees.

less than

Nonbonding electron pairs are also referred to as ____ pairs.

lone

In the formation of ionic compounds a metal will ____ electrons and a nonmetal will ____ electrons to form an ion with the same number of electrons as the nearest ____ gas.

lose; gain; noble

Chemists use the ____ as a unit of amount of substance.

mole

One ____ of any substance contains Avogadro's number of particle.

mole

The molar mass of any substance is the mass of 1 ____ of the particles of that substance.

mole

In general, a lone pair occupies ____ space than a bonding electron pair, and will therefore ____ the bond angle between bonding pairs.

more; decrease

Consider the balanced equation 2H2 + O2 -> 2H2O. The coefficients (numbers in front of the formulas) correspond to the number of particles of each substance involved in the reaction, which is proportional to the ____ of each substance.

number of moles

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, valence, mutually repelling or repelling; repulsion(s) or interaction

A unit that contains two or more elements covalently bonded together but that has an overall charge is called a(n) ____ ion. Many ___ compounds contain such units

polyatomic; ionic

Which of the following can be attributed to the atmosphere of planet Earth?

the Earth's average temperature is higher than expected when considering its distance from the Sun

Which statement correctly describes the procedure used to predict the ion formed by Group 1 and Group 2 elements?

the metal loses enough electrons to attain the same number as its nearest noble gas

Organic chemistry is ____.

the study and production of carbon-containing compounds

Electronegativity generally increases ____ on the periodic table, excluding noble gases.

up and to the right

Ice core data shows that atmospheric CO2 levels _____.

were relatively constant from the beginning of the last millennium until around 1800

What charge will the ion formed from barium have?

+2

Which of the following are three-dimensional representations of a molecule? Select all that apply.

-Space filling model -wedge dash representation

Which of the following options correctly describe albedo? Select all that apply.

-The albedo of the Earth affects global temperatures. -Albedo is the fraction of incoming radiation that is reflected by a surface. -A more reflective surface will have a higher albedo than a less reflective one.

Which of the following conclusions were reached by the IPCC (International Panel on Climate Change)? Select all that apply.

-The burning of fossil fuels has a major impact on climate change. -Human activities play an important role in climate change. -The average global temperature of the Earth is increasing.

Match each metal ion to the correct Roman numeral that would be used when naming an ionic compound when appropriate.

... (III) - Fe3+ ... (II) - Cr2+ ... none - Zn2+ ... (I) - Cu+

Which of the following options correctly interpret the information provided by the balanced equation CH4 + 2O2 -> co2 + 2h2o? Select all that apply.

... 1 mole of CH4 produces 1 mole of CO2 when reacted with 2 moles of O2 ... 15 mol of CH4 will produce 15 mol of CO2 when burned completely in O2 ... 1 molecule of CH4 reacts with 2 molecules of O2

Which of the following ion combinations will result in an ionic compound that has a balanced number of positive and negative charges? Select all that apply.

... 2 Li+ and S2- ... Na+ and Br- ... Ca2+ and 2F-

Match each compound correctly to its molar mass. Round all atomic masses read from the periodic table to one place after the decimal.

... CCl4: 154.0 g/mol ... PF3: 88.0 g/mol ... SO2: 64.1 gm/mol

Which of the following formulas for ionic compounds are correct? Select all that apply.

... Ca3N2 ... CaO

In the compound CrCl3 ____. Select all that apply.

... Cl has a -1 charge ... Cr has a +3 charge

Match each element with the appropriate charge in its ionic form.

... Cl: -1 ... Sr: +2 ... S: -2 ... Al: +3

Which of the following statements correctly describe ions? Select all that apply.

... F- is an example of an anion ... ions are formed when atoms lose or gain electrons

Which of the following options correctly describe the interaction of a molecule with IR radiation? Select all that apply.

... 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

Match each of the following polyatomic ion with its correct name.

... OH- is hydroxide ... NO2- is nitrite ... NO3- is nitrate ... PO43- is phosphate ... SO42- is sulfate ... SO32- is sulfite

Which of the following options correctly relate the number of outer electron groups in a molecule to its observed shape? Select all that apply.

... a linear shape is observed for a molecule with two bonding electron groups and no lone pairs ... a molecule with two bonding and two nonbonding electron pairs will be bent

An atom may lose or gain electrons to form an ion. Match each description of ions and their charges correctly.

... anion: an ion with more electrons than its neutral atom ... cation: an ion with fewer electrons than its neutral atom ... negative: the charge of an ion with more electrons than its neutral atom ... positive: the charge of an ion with fewer electrons than its neutral atom

Which of the following options correctly describe atomic mass? Select all that apply.

... atomic masses are defined relative to the mass of a carbon-12 atom ... the atomic mass of an element can be read from the periodic table

Which statements describe an ionic compound? Select all that apply.

... compounds formed when metals combine with nonmetals ... compounds that contain no molecules

Match each type of bond to the correct description given.

... covalent bond: attraction between two nuclei and a shared pair of electrons ... ionic bond: attraction between oppositely charged ions

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 and nonbonding electron pairs with respect to each other

Which polyatomic ions are anions? Select all that apply.

... hypochlorite ... nitrite ... acetate ... bicarbonate ... hydroxide

Which of the following options describe the correct format used to represent a chemical compound? Select all that apply.

... 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

Which of the following statements correctly describe ions? Select all that apply.

... ions are formed when atoms lose or gain electrons ... F- is an example of an anion

In chemistry, the mole ____. Select all that apply.

... is abbreviated mol ... indicates amount of substance

Match each element in the compound NH3 to its correct mass ratio and mass percentage.

... mass ratio of N: 0.824 ... mass percent of N: 82.4 ... mass ratio of H: 0.176 ... mass percent of H: 17.6

Which of the following options correctly describe each type of chemical compound? Select all that apply.

... nonmetals combine with metals to form ionic compounds ... molecular compounds tend to contain nonmetals only

Which of the following human activities increase the levels of atmospheric CO2? Select all that apply.

... replacing trees with cultivated crops ... burning fossil fuels ... respiration

Match the number of outer electron groups correctly to the molecular shape observed.

... tetrahedral has 4 bonding pairs ... trigonal pyramidal has 3 bonding pairs and 1 lone pair ... linear has 2 bonding pairs ... bent has 2 bonding pairs and 2 lone pairs ... trigonal planar has 3 bonding pairs

Which of the following options correctly describe the steps required to determine the shape of a molecule? Select all that apply.

... the Lewis structure of the molecule must be drawn first ... both bonding and nonbonding electron pairs must be considered ... the shape of the molecule is dictated by the most stable arrangement of the outer electron pairs

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

Which of the following options explain why the term "global warming" is considered inaccurate by some scientists? Select all that apply.

... the term "global warming" could be thought to describe a benign influence ... the effects of global warming vary across the globe

Which of the following options correctly interpret the information given? Select all that apply. Molar mass of NO2 = 46.0 g/mol; molar mass of nitrogen 14.0 g/mil; molar mass of oxygen = 16.0 g/mol.

... there are 14.0 g of nitrogen in every 46.0 g of NO2 ... the percentage oxygen in NO2 is equal to 32.0/46.0 x 100% ... the percentage of nitrogen in NO2 is equal to 30.4%

The periodic table lists the atomic mass of nitrogen as 14.01. Which of the following options correctly interpret this value?

... this is the average mass of an atom of nitrogen ... this value takes into account the masses and abundances of the isotopes of nitrogen

Which of the following are three-dimensional representation of a molecule? Select all that apply.

... wedge-wash representation ... space-filling model

Match each molecular shape correctly to its associated bond angle.

.... tetrahedral: 109.5 degrees ... trigonal planar: 120 degrees ... linear: 180 degrees ... trigonal pyramidal: less than 109.5 degrees

Which of the following reflects the correct procedure to calculate the molar mass of CH2Cl2?

12.0 + 2(1.0) + 2(35.5) = 85.0 g/mol

Which of the following greenhouse gases would require a wedge and dash representation in order to accurately depict its shape?

CCl2F2

In order for a molecule to absorb IR radiation, which of the following must be true?

its bond vibrations must involve a change in charge distribution