chem 101 exam 2

An ion with fewer electrons than its neutral atom is called a(n)

cation

the following polyatomic ions with its correct name: Acetate

C2H3O2-

appropriate charge in its ionic form: Cl

-1

appropriate charge in its ionic form: S

-2

trigonal planar

120

linear

180

Microwave

Causes the molecule to spin faster

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.)

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

The chemistry of carbon-based compounds is called ______ chemistry.

organic

Which of the following is NOT a greenhouse gas?

N2

Which gases have shown concentration changes in the atmosphere that correlate with global temperature changes? Select all that apply.

N2O CO2 CH4

the following polyatomic ions with its correct name: Ammonium

NH4+

Which of the following options correctly describe the effect of different types of radiation on a molecule?(Select all that apply.)

Radiation that has a longer wavelength than IR radiation causes molecules to spin faster. UV radiation may cause a molecule to dissociate. Bonds can be broken by radiation with higher frequencies than visible light.

Which of the following processes release CO2 into the atmosphere? Select all that apply.

Respiration Decomposition Combustion

Which of the following human activities increase the levels of atmospheric CO2?

Respiration Replacing trees with cultivated crops Burning fossil fuels

Which event corresponded with an increase in the rate of accumulation carbon dioxide in ice cores?

The Industrial Revolution

Which of the following options correctly describe the changes observed in global temperature over time? Select all that apply.

The average global temperature has increased over the same period as atmospheric CO2 levels have increased. The average global temperature of the Earth has increased over the past century.

Which of the following options correctly describe a polyatomic ion? Select all that apply.

The charge on a polyatomic ion belongs to the whole unit. The atoms of a polyatomic ion are held together by covalent bonds.

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+.

Solvent

The majority component of the solution

Solute

The minority component of the solution

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 differentiate between weather and climate? Select all that apply.

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

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

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. IR radiation can excite both bending and stretching vibrations.

Which of the following options correctly describe the electron groups and geometry of the molecule shown? Select all that apply.

There are 4 electron groups around the central P atom. This molecule is trigonal pyramidal in shape.

Which of the following correctly reflects Avogadro's number?

There are 6.02 x 1023 atoms in 12 g of carbon-12.

Which of the following options correctly describe the expected greenhouse gas activity of CH2Cl2? Select all that apply.

This molecule will absorb IR radiation and can behave as a greenhouse gas. This molecule can undergo bending vibrations that will absorb IR radiation.

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

Wedge-dash representation Space-filling model

the correct Roman numeral that would be used when naming an ionic compound when appropriate: none

Zn2+

A precipitate is _______.

a solid that separates from solution

An ion with more electrons than its neutral atom is called a(n)

anion

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

Ionic bond

attraction between oppositely charged ions

Natural locations that store carbon, usually in the form of one of its compounds, and that naturally exchange carbon with each other are known as ______.

carbon reservoirs

Which of the following options are correct systematic names for ionic compounds? Select all that apply.

copper(II) oxide potassium chloride

Weather

describes events of relatively short duration, including daily high and low temperatures.

Climate

describes regional events recorded over longer periods.

The most important greenhouse gas on Earth is carbon_______

dioxide

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

gain; noble

A gas that is able to absorb and trap infrared radiation, resulting in a warming of the atmosphere, is called a(n) gas.

greenhouse

Water has many unique properties. These anomalies include a _____ boiling point and a tendency to _____ on freezing.

high; expand

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

huge

the following polyatomic ions with its correct name: OH-

hydroxide

b

in front of the plane of the page

a

in the plane of the page

An infrared spectrum records ______.

intensity of transmitted radiation vs. wavelength

n 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 accuracy of a calculation is limited by the quantity that has the _____ number of significant figures.

least

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 109.5o.

less than

trigonal pyramidal

less than 109.5

The organic material that decomposed to form fossil fuels has a very _____ level of carbon-14. Burning fossil fuels therefore causes a(n) _____ in the levels of carbon-14 in atmospheric CO2.

low; decrease

H2O molecules containing the isotope 2H condense _____ readily than H2O molecules containing 1H, causing snow and ice to be enriched in _____ when compared to ocean water. The 2H/1H ratio in ice depends on temperature, and this value can be measured and used to estimate the temperature at the time the ice formed.

more; 2H

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

more; decrease

The charge of an ion with more electrons than its neutral atom is

negative

the following polyatomic ions with its correct name: NO3-

nitrate

the following polyatomic ions with its correct name: NO2-

nitrite

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 following polyatomic ions with its correct name: PO43-

phosphate

In order to predict if a given molecule can act as a greenhouse gas, we must determine its molecular_________ using the Lewis structure.

shape

A ___________ is a homogeneous mixtures of a solvent and one or more solutes.

solution

space filling model

space filling model

Organic chemistry is _______.

the study and production of carbon-containing compounds

3 bonding pairs

trigonal planar

The molecule shown has a _____ shape and the marked bond angle is approximately _____.

trigonal planar; 120

3 bonding pairs and 1 lone pair

trigonal pyramidal

True or false: The central oxygen atom of the ozone molecule (shown) is surrounded by three electron groups.

true

Electronegativity generally increases _______ on the periodic table, excluding noble gases

up and to the right

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 # 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 shape of the molecule by examining the position of the bonding and nonbonding electron pairs with respect to each other.

The atomic mass of magnesium is 24.31 g. Given that Avogadro's number is 6.02 x 1023, what is the average mass of one Mg atom?

4.04 x 10-23 g

There are exactly ____ x 1023 atoms in 12 g of carbon-12 (given to TWO places after the decimal). This number is called ________ number.

6.02; Avogadro's

According to the USGS, how much water per day is needed by the average U.S. citizen?

> 390L

A molecule will absorb IR radiation if it is capable of vibrational mode _____. (Select all that apply.)

A C D

What is a significant figure?

A digit that represents the precision with which an experimental quantity is known

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 polyatomic ions are anions? (Select all that apply.)

Acetate Nitrite Hydroxide Hypochlorite Bicarbonate

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

UV radiation

Breaks bonds, causing the molecule to dissociate

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

Burning fossil fuels

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

CCl2F2

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

CO2

Which of the following are common greenhouse gases? Select all that apply.

CO2 H2O methane (CH4)

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

CO2 is generated by the combustion of fossil fuels. The main atmospheric form of carbon is CO2.

In the compound CrCl3 _______. (Select all that apply.)

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

the correct Roman numeral that would be used when naming an ionic compound when appropriate: (II)

Cr2+

the correct Roman numeral that would be used when naming an ionic compound when appropriate: (I)

Cu+

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.

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.

tetrahedral

109.5

The isotope Mg-25 isotope has _____ protons and _____ neutrons in its nucleus. Mg has an atomic number of 12.

12; 13

the correct Roman numeral that would be used when naming an ionic compound when appropriate: (III)

Fe3+

What is the difference between the terms global warming and climate change?

Global warming is one aspect of climate change.

covalent bond

attraction between two nuclei and a shared pair of electrons

c

behind the plane of the page

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

The charge of an ion with fewer electrons than its neutral atom is

positive

What is the correct systematic name for the compound Na2CO3?

sodium carbonate

The component that is the most abundant in a solution is called the _________________ , whereas any dissolved substance is called a __________________

solvent; solute

the following polyatomic ions with its correct name: SO42-

sulfate

Methane has a _____ shape.

tetrahedral

Ice core data shows that atmospheric CO2 levels ____

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

appropriate charge in its ionic form: Sr

+2

Which of the following statements correctly define a solution? Select all that apply.

-A solution can contain one or more solutes. -Solutes may be liquids, solids, or gases. -A solution is a homogeneous mixture.

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

-The molar mass of oxygen is 16.00 g/mol. This 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.

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

-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 options correctly describe the isotope Cr-53,if the element Cr (chromium) has an atomic number of 24? Select all that apply.

-This isotope contains 29 neutrons in its nucleus. -The element contains 24 protons in its nucleus.

The standard temperature and pressure for reporting properties such as density are _____ and _______.

25°C 1 atm

How can ice-core data provide information about changes in atmospheric CO2 levels over time?

Air bubbles trapped in the ice are analyzed to determine the CO2 content at a particular time period.

Which of the following sources provide information about atmospheric CO2 levels over time? Select all that apply.

Direct atmospheric measurements Data obtained from air bubbles trapped in ice cores

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.

In order to be a greenhouse gas, a molecule must _____. (Select all that apply.)

be composed of three or more different atoms undergo a change in overall charge distribution during vibration

2 bonding pairs and 2 lone pairs

bent

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

carbon

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

Which statement about ice cores is correct?

deepest are oldest

lewis structure

lewis structure

2 bonding pairs

linear

The process whereby a solid forms and separates from solution is called ______________

precipitation

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

-Atmospheric gases trap and return more than 80% of the heat radiated by Earth. -This effect has resulted in an increase in average global temperatures on Earth.

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

-Each element's atomic mass is a weighted average of the masses of the elements' isotopes. -Isotopes have different numbers of neutrons.

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

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

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.

Carbon reservoirs _______. (Select all that apply.)

-usually contain carbon in the form of one of its compounds -exchange forms of carbon with each other

Approximately how much water per day is required to support the lifestyle of the average U.S. citizen, according to the U.S. Geological Survey?

100 gallons

How many significant figures should the answer to the following calculation contain? 2.3 x 5.46 = _____

2

What ratio is analyzed to provide data for estimating temperatures?

2H:1H

The correct answer to the mathematical expression 1016 x 1014 is 10 _____. The correct answer to the mathematical expression 10161014 is 10 _____.

30; 2

The atomic mass of calcium is 40.08 g. Given that Avogadro's number is 6.02 x 1023, what is the average mass of 15 Ca atoms?

9.99 x 10-22 g

Which of the following options correctly describes a greenhouse gas?

A gas that absorbs and traps infrared radiation, thus warming the atmosphere

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.

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

Which of the following is an anthropogenic influence on the environment? (Select all that apply.)

Airline transportation Diamond mining Landfills Cattle farming

Which of the following options correctly explain how carbon-14 levels can provide information about the source of atmospheric CO2? Select all that apply.

CO2 produced by burning of fossil fuels contains virtually no carbon-14. CO2 produced by burning fossil fuels causes the carbon-14 levels in the atmosphere to decrease.

the following polyatomic ions with its correct name: Carbonate

CO32-

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

CaO Ca3N2

the following polyatomic ions with its correct name: Hypochlorite

ClO-

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

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

Which of the following CANNOT act as a greenhouse gas? Select all that apply.

H2 Cl2

the following polyatomic ions with its correct name: Bicarbonate

HCO3-

Rank the following compounds, from lowest to highest boiling points. For your ranking, place the lowest-boiling compound on the top.

HCl HBr HI

Any gas that can absorb ____________ radiation can act as a greenhouse gas. (The answer is one word.)

IR

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

NaNO3 Mg3(PO4)2 CaCO3

Which of the following options correctly describes the effects of the observed increase in global temperatures over the last century?

On average the planet is warmer than it was a century ago.

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 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.

Which statement correctly describes the procedure used to predict the ion formed by nonmetal elements in Groups 15, 16, and 17?

The nonmetal gains enough electrons to attain the same number as its nearest noble gas.

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

The process by which atmospheric gases trap and return more than 80% of the heat energy radiated by Earth is called the ___________ greenhouse effect, resulting in an increase in average global temperatures.

enhanced

True or false: When mathematically manipulating pieces of data, the quantity with the most significant figures determines the accuracy of the calculation.

false

The most electronegative element is _______.

fluorine

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

What is the correct systematic name for the ionic compound Li3N?

lithium nitride

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

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 particles.

mole

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

mole

The most stable molecular arrangement is the one in which the ____________ electron groups are as far apart as possible, to minimize electron-electron ___________.

outer; interaction

Direct measurements of atmospheric CO2 levels in Hawaii show that since 1960 _____. (Select all the options that complete the sentence correctly.)

the annual average CO2 levels have increased steadily the CO2 levels in a given year fluctuate depending on the time of year

ce core data shows that atmospheric CO2 levels _____.

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

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 statements correctly describe the mole? Select all that apply.

-One mole of any substance contains 6.02 x 1023 particles. -The number of particles in a mole is called Avogadro's number.

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

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

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

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

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

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

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

109.5 degrees

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

Ozone is able to act as a greenhouse gas because its _____ shape allows it to vibrate in ways that involve _____ in overall charge distribution.

bent; change

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

A ________ figure is a digit that represents the accuracy with which an experimental quantity is known.

significant

What charge will the ion formed from barium have?

+2

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

+2; -2

appropriate charge in its ionic form: Al

+3

Which of the following options correctly interpret the information provided by the balanced equation CH4 + 2O2 → CO2 + 2H2O? (Select all that apply.)

-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. -1 mole of CH4 produces 1 mole of CO2 when reacted with 2 moles of O2.

The CO2 molecule (shown) has a linear shape, which is consistent with _____ electron groups around the central carbon atom. The four electrons of each double bond therefore count as _____ electron group.

2;1

IR radiation

Causes the molecule to vibrate

What type of radiation is absorbed by all greenhouse gases?

IR radiation

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.

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

Rb Ca

Influences on the environment resulting from human activities are called _____ influences.

anthropogenic

Increased temperatures correlate with ____ atmospheric concentrations of methane.

increased

In general, for molecular compounds of similar type, as the molar mass _____ the boiling point increases.

increases

molecular formula

molecular formula

the following polyatomic ions with its correct name: SO32-

sulfite

4 bonding pairs

tetrahedral

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

-indicates amount of substance -is abbreviated mol