CHM265 Ch.1 Reading Questions

cradle-to-grave

An approach to analyzing the life cycle of an item, beginning with the raw materials from which it is made to its ultimate disposal, is called the _____ approach.

cradle-to-cradle

An approach to consumer goods that aims at recycling, so that the end of the life cycle of one item leads naturally into the beginning of the life cycle of another, is the ___ approach.

17, 19

An atom of chlorine (Cl) has a mass number of 36. This atom has ___ protons and ___ neutrons in its nucleus.

ions electrons

An electric current is the net movement of _____.

insulator

Does not allow the flow of electricity

Element= one atom Compound=two atoms of different elements bonded together

Element= Compound=

conductor

Enables the flow of electricity

noble gases

Generally unreactive

metal

Good conductor of heat and electricity

alkali metals

Make soil and water alkaline

chemical compounds found in rocks and soil

Minerals are _____.

The proportions of the components can vary The components can be separated by physical means

Mixtures...

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

Molar mass of NO2=46.0 g/mol; molar mass of nitrogen=14.0 g/mol; molar mass of oxygen=16.0 g/mol.

electron

Negatively charged particles

mixture

Physical combination of two or more species

nonmetal

Poor conductor of heat and electricity

Quartz

Pure crystallized SiO2 with a highly ordered arrangement at the atomic level

Glass

Random array of silicon and oxygen linkages throughout the solid

alkaline earth metals

Result in hard water

10

Scientific notation expresses a quantity with a single digit before the decimal point and followed by ____ raised to the appropriate power.

F,T,T,F

T/F The chemical symbol for iron is I T/F The chemical symbol for argon is Ar T/F The chemical symbol for carbon is C T/F The chemical symbol for cobalt is CO

mass, neutrons

The ____ number of an atom is equal to the total number of protons and ___ in the nucleus of the atom.

least

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

Is equal to the number of protons in the nucleus Each element has its own unique atomic number

The atomic number of an element...

mole

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

contains the chemical symbols that represent the elements the elements in the periodic table are arranged based on similar chemical properties

The periodic table...

The sum of the oxidation numbers for the atoms in a neutral compound is zero The ON for a monatomic ion is the same as its charge

The rules for assigning oxidation numbers (ON):

mass, charge

To balance a half-reaction, the number and type of each element present is balanced to reflect the conservation of _____ in the reaction. Electrons are added to the appropriate side of the equation to reflect the conservation of _____.

20 nm x 1 x 10^-9 __________ 1 nm

To convert from 20nm to m, given that 1nm=1 x 10^-9 m, set up the equation as:

+4

What is the oxidation number of S in SO2?

+2

What is the oxidation number of iron in FeO?

the number of atoms of a particular element is indicated by a subscript A chemical formula is a symbolic way to represent the composition of a substance

When writing the chemical formula of a substance...

Hydrogen, Oxygen, Nitrogen, and Fluorine

Which element commonly occurs as a diatomic molecule?

O2 O3

Which of the following are allotropes of oxygen?

pure substance

form of matter with a definite composition

reduction

gain of electrons

oxidation

loss of electrons

proton

positively charged particle found within the center of the atom

neutron

uncharged dense particle located in the center of the atom

significant

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

molecule

A ______ is independent structure consisting of two or more atoms chemically bonded together

formula

A chemical ____ (CO2) represents the elementary composition of any pure substance.

equivalent, 1

A conversion factor is ratio of _____ quantities used to express a quantity in different units of measurement. Multiplying by a conversion factor is the same as multiplying a quantity by ____ because the numerator and denominator are equivalent.

are extremely small compounds contain two or more different types of atoms An atom is the smallest unit of an element that can exist as a stable, independent entity

Atoms...

mass, space

Chemistry is the study of matter, which is commonly defined as anything that has ____ and occupies ______.

mole

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

air=mixture O2= pure substance

Classify air and oxygen (O2) as mixture or pure substance

Covalent compound=CO2, N2O5, PCl3 ionic compound=NaBr, FeCl3, NiO

Classify each compound as either covalent or ionic compound: NaBr, CO2, FeCl3, NiO, N2O5, PCl3

Ne-noble gas Cl-halogen Cu-metal

Classify each element correctly according to its type and/or the group it belongs to: Ne, Cl, Cu

Molecular Compound=composed of molecules, formed when nonmetals combine Ionic Compound=contains no molecules, formed when metals combine with nonmetals

Classify each item as molecular (covalent) compound or ionic compound: composed of molecules, contains no molecules, formed when nonmetals combine, formed when metals combine with nonmetals

Pure substance=pure silver coin, hydrogen gas, H20 mixture=salt water, gold-plated earrings

Classify each item as pure substance or mixture: salt water, pure silver coin, hydrogen gas, H20, gold-plated earrings Pure substance= mixture=

Conductor= gold, silver, copper Semiconductors= GaAs, Si, CdS insulator= plastic, concrete

Classify each material as conductor, semiconductor, or insulator based on its ability to enable the flow of electricity: GaAs, Si, plastic, concrete, gold, silver, copper, CdS

homogeneous-salt water, air heterogeneous-bean soup, soil mixed with rocks, pasta salad

Classify each of the following as a homogeneous or heterogenous mixture: air, salt water, bean soup, soil mixed with rocks, pasta salad

O3-element H2O-compound air-mixture

Classify each substance as compound, mixture, or element: O3, H20, air

Compound=two different atoms bonded together element=atoms on their own

Compound= element=

compound

Consists of two or more elements, chemically bound

element

Contains only one type of atom

gain, lose

Copper occurs in a variety of compounds in ores. Chalcocite is a mineral composed of Cu2S. In order to extract solid Cu metal from this ore, the Cu ions must ___ electrons and the S2- ions must ____ electrons.

8.35 x 10^-11

Express the quantity 0.0000000000835 (10 0s) correctly in scientific notation.

taps into a source that is far more concentrated than metal ores mined from the ground

Extracting metals by recycling electron devices...

Many metals exist as compounds of oxygen, or oxides Nonmetals such as oxygen and nitrogen may occur either in elemental form or in the form of compounds

Form(s) in which elements exist in nature:

metalloid

Has properties between those metals and nonmetals

2

How many significant figures should the answer to the following calculation contain? 2.3 x 5.26

elements, fixed

In a given chemical compound, the component ____ are present in _____ proportions by mass, regardless of the source of the compound.

is abbreviated mol indicates amount of substance

In chemistry, the mole

+2, -2

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

sustainability

Managing human consumption of natural resources so that these resources are not exhausted is called ____.

oxide, silicate

Many metals occur as minerals in rocks and soil. A mineral in which a metal is bonded to oxygen is called a(n) _______, whereas a mineral containing oxygen and silicon together is called a(n)___

CCl4=154.0 g/mol PF3= 88.0 g/mol SO2= 64.1 g/mol

Match each compound correctly to its molar mass: CCl4, PF3, SO2, 154.0g/mol, 88.0 g/mol, 64.1 g/mol

mass ratio of N-0.824 mass percent of N-82.4 mass ratio of H-0.176 mass percent of H-17.6

Match each element in the compound NH3 to its correct mass ratio and mass percentage: 17.6, 82.4, 0.176, 0.824

O in O2= 0 Na in NaCl= +1 O in H2O= -2 Fe in FeCl3= +3

Match each element to its correct oxidation number: O in O2, Na in NaCl, O in H2O, Fe in FeCl3

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

Match each element with the appropriate charge in its ionic form: Cl, Sr, S, Al

Group 1A-Alkali metals Group 2A-Alkaline earth metals Group 7A-Halogens Group 8A-Noble Gases

Match each group in the periodic table with the correct name as indicated Group 1A- Group 2A- Group 7A- Group 8A-

He-2 Al-13 Zn-30 Rn-86

Rank the following elements correctly according to its number of protons, starting with the element that has the least number of protons at the top of the list: Zn, Rn, Al, He

is denser than glass is produced by heating aluminum oxide powder to very high temperatures

Synthetic sapphire...

1, 4

The chemical formula CCl4 indicates that there is/are ____ carbon atom(s) for every ____ chlorine atom(s)

hundred

The composition of a mixture may be expressed as a percentage. Percent means parts per

12.o g C ————- x 100% 85.o g CH2Cl2

The molar mass of CH2Cl2 is 85.0 g/mol, wile the molar mass of carbon is 12.0 g/mol. The percent of carbon in this compound is correctly expressed as

oxidation

To track the transfer of electrons in both ionic and molecular substances, we assign a(n)_____ number to each element involved. This number reflects the charge the element would have if all bonds were ionic.

ppm=parts per 10^6 parts (million) ppb=parts per 10^9 parts (billion) ppt= parts per 10^12 parts (trillion)

We often use units of ppm, ppb, and ppt to express very low concentrations. Match each unit to its correct definition: parts per 10^9 parts, parts per 10^6 parts, and parts per 10^12 parts

groundwater could be contaminated with heavy metals the solvents used to remove the plastics are not generally environmentally friendly contaminated groundwater could contribute to an increase of cancers in surrounding communities

What are the environmental challenges to extracting metals from recycled electronic devices?

number of atoms, electrons

When balancing a half-reaction, the conservation of mass is reflected by balancing the ___ on both sides of the equation, while the conservation of charge is reflected by adding ___ to the appropriate side of the reaction.

Cerium and Gadolinium

Which are rare earth metals? Gold, Cerium, Calcium, Gadolinium

There are many more known compounds than elements A compound contains two or more different elements Elements and compounds are both pure substances

Which describes an element and compound.

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

Which ion combinations will result in an ionic compound that has a balanced number of positive and negative charges? Mg2+ and Cl-, Na+ and Br-, Ca2+ and 2F-, K+ and O2-, 2 Li+ and S2-

silicon

Which metalloid is a key component of electronic devices?

This approach assumes that consumer goods will not be recycled This approach does not encourage sustainable practices

Which of the following are limitations to the "cradle-to-grave" approach to analysis of consumer goods?

Fe2+ > Fe3+ + e-

Which of the following equations represents an oxidation half-reaction? Na+ + e- > Na, Fe2+ > Fe3+ + e-, Cl2 + 2 e- > 2 Cl

Chemical symbols are also called atomic symbols Chemical symbols are abbreviations for elements named for properties, planets, places, and people

Which of the following options correctly describe the chemical symbols for elements?

The molar mass of a molecular substance is the mass per moles of its molecules The periodic table can be used to calculate the molar mass of any substance 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.

Which of the following statements correctly describe molar mass?

The nonmetal gains 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?

mixture= physical combination of two more species pure substance= form of matter with a definite composition

mixture= pure substance=

nucleus

small region that contains almost all the mass of an atom