Exam 3 Terms- GSCI 115
Photons of which of the following colors of light possess the greatest amount of energy?
Blue
Since wood is composed of carbohydrates, you should expect which gases to exhaust from a fireplace when complete combustion takes place?
Carbon dioxide and water vapor
The correct name for the compound CS2 is (2 is subscript)
Carbon disulfide
Which of the following is an example of a monatomic molecule?
Ar
The smallest unit of an element that can exist alone or in combination with other elements is an
Atom
*Question for Thought* An Atom has 11 protons in the nucleus. What is the atomic number? What is the name of this element/ What is the electron configuration of this atom?
Atomic #: 11 Element: Sodium Electronic Configuration: 1s2 2s2 2p6 3s1
The law of conservation of mass means that
Atoms are not lost or destroyed in a chemical reaction.
To what chemical reaction class does this reaction belong? CaCO2(s) --> CaO(s) + CO2 (g)
Decomposition
The energy of a photon of light emitted by an electron equals the
Difference in energy between two level
The most important factor in the chemical behavior of an atom is the
Electron Structure
The comparative ability of atoms of an element to attract bonding electrons is called
Electronegativity
*CHAPTER 8* Elements in the same row of the periodic table exhibit similar chemical properties
False
An atom becomes a positive ion by gaining an electron.
False
Einstein proposed that electrons on the surface of a metal gradually absorb energy from a photon until they have enough energy to leave the surface.
False
Ionic bonds occur between atoms from adjacent groups.
False
Substances that lose electrons in reactions are called oxidizing agents.
False
The -ide ending in nitrogen dioxide tells you that this is an ionic compound.
False
The atomic number of an element is the total number of protons and neutrons in the nucleus.
False
The empirical formula gives the actual number of atoms of each kind in a compound.
False
The subscript "2" in Mg(OH)2 tells you that the charge of the hydroxide ion is (-2).
False
When balancing a chemical equation, you need to change subscripts to make the number of atoms of an element the same on both sides of the equation.
False
A nonmetal atom combines with a second nonmetal atom. The first nonmetal atom
Shares electrons with the second nonmetal atom
*CHAPTER 10* When compounds containing carbon and hydrogen are burned in air, the products are usually carbon dioxide and water.
True
*CHAPTER 9* Atoms gain or lose electrons in order to attain a valence orbital arrangement like that of a noble gas.
True
A covalent bond is a shared pair of electrons.
True
An electron moves from one orbital to another only when it absorbs or emits energy.
True
Protons and neutrons have about the same mass.
True
Protons are so much more massive than electrons that you can neglect the mass of electrons when determining the mass of an atom.
True
The word halogen comes from the Greek, meaning salt-former.
True
Three hydroxide ions are needed to form a neutral ionic compound with an aluminum ion.
True
When balancing a chemical equation, the number of H atoms in 2 CH4 is eight.
True
According to Rutherford's calculations, the volume of an atom is mostly
Filled with empty space
Atoms of the representative elements have a tendency to seek stability through
Filling or emptying their outer orbitals
An ion can be described as an element or compound that
Gains or loses electrons
The amount of energy released when wood is burned is
equal to the amount of solar energy absorbed during its formation
A photon is emitted from the electronic structure of an atom when an electron
jumps from a higher to a lower energy level.
The formation of a positive ion
occurs when an electron is removed from an atom.
An oxidizing agent is a substance that
removes electrons from another substance
Isotopes of an element are atoms that have
the same number of protons, but a different number of neutrons.
Hydrogen, with its one electron, can produce a line spectrum with four visible colors because
there are multiple energy levels that an electron can occupy.
What is the chemical symbol of a magnesium ion?
Mg ^2+
What is the correct formula for magnesium chloride?
MgCl2 (2 is subscript)
Any substance that contains Avogadro's number of particles is called a
Mole
The smallest particle of a compound or gaseous element that can exist and still retain the characteristic properties of that substance is a
Molecule
The atomic weight of neon is 20.2. This means:
Neon occurs as isotopes of different masses and the weighted average is 20.2 u.
Identify the number of protons, neutrons, and electrons in the following isotopes:
(a) *12/6 C* Protons 6, Neutrons 6, Electrons 6 (b) *1/1 H* Protons 1, Neutrons 0, Electrons 1 *Protium, which contains a single proton and a single electron, is the simplest atom* (c) *40/18 Ar* Protons 18, Neutrons 22, Electrons 18 (d) *2/1 H* Protons 1, Neutrons 1, Electrons 1 (e) *197/79 Au* Protons 79, Neutrons 118, Electrons 79 (f) *235/92 U* Protons 92, Neutrons 143, Electrons 92
Refer to figure 8.16 only, and write the complete electron configurations for (a) argon, (b) zinc, and (c) bromine.
(a) 1s2 2s2 2p6 3s2 3p6 (b) 1s2 2s2 2p6 3s2 3p6 3d10 4s2 (c) 1s2 2s2 2p6 3s2 3p6 3d10 4s2 2p5
Which of the following is NOT an example of a chemical reaction?
*A. Blending of a vanilla milkshake* B. Growing tomatoes C. Burning logs in the fireplace D. Digesting your dinner
An atom of an element in family VIA will have what charge when it is ionized?
-2
An inorganic compound made of only 2 different elements has a systematic name that always ends with the suffix
-ide
What are the coefficients needed to balance this chemical equation? ____CaCl2 + _____KOH --> ____Ca(OH)2 + ____KCI
1, 2, 1, 2
What is the total number of atoms in calcium phosphate, Ca3(PO4)2?
13
What is the formula weight of methane, CH4?
16u
What are the coefficients needed to balance this chemical equation? ___C2H6(g) + ___O2(g) --> ___CO2 + _____H20 (g)
2,7,4,6
Which reaction is an example of a combination reaction?
4 Fe(s) + 3 O2(s) --> Fe2O2 (g)
What is the mass percent of sodium in washing soda, Na2CO3?
43.4%
How many valence electrons does the element nitrogen (N) have?
5
If you have 6.02 X 10^23 atoms of metallic iron, you will have how many grams of iron?
55.85
What is the formula weight of magnesium hydroxide, an ingredient found in antacids?
58.3 u
The equation 2 C2H5OH + __O2 --> 4 CO2 + 6 H2O is balanced by making the coefficient of oxygen
6
What is the formula weight of acetic acid, CH2COOH, which is found in vinegar?
60.0 u
When the equation __Li + __O2 --> ___Li2O is correctly balanced, what is the sum of the coefficients?
7
What is the formula weight of aluminum hydroxide, Al(OH)3?
78u
The mass of oxygen in 5 moles of water is
80g (16g x 5)
What is the total mass of products in the methane reaction shown below? CH4 + 2O2 --> CO2 + 2H2O
80u
How many atoms of oxygen are in a molecule of Al2(CO3)3?
9
What is the number of atoms on each side of the equation? CH4 + 2O2 --> CO2 + 2H2O
9
*Ch 9 Applying the Concepts:* Which of the following is NOT true of a compound? It is
A. A pure substance B. Composed of combinations of atoms C. Held togther by chemical bonds *D. A substance that cannot be broken down into simpler units*
Which is NOT trust of an ionic bond? It involves
A. A transfer of electrons *B. Sharing of electrons* C. Electrostatic attraction between ions D. Metals and nonmetals
Which of the following does NOT have an ionic bond?
A. BaCl2 B. Na20 *C. CS2* D. BaS (2s are subscripts)
Write complete, balance equations for each of the following reactions: A. C5H12 + 02 --> B. HCl + NaOH --> C. Al + Fe2O3 --> D. Fe + CuSO4 --> E. MgCl2 + Fe(NO3)2 --> F. C6H10O5 + O2 -->
A. C5H12 + 8O2 --> 5 CO2 + 6 H20 B. HCl + NaOH --> NaCl + H20 C. 2 Al + Fe2O3 --> Al2O3 + 2 Fe D. Fe + CuSO4 --> FeSO4 + Cu E. MgCl2 + Fe(NO3) --> no reaction; all possible compounds are soluble and no gas or water was formed F. C6H10O5 + 6 O2 --> 6 CO2 + 5H20
What is the formula weight for each of the following compounds?
A. Copper (II) sulfide: 95.6u (64 + 32) B. Carbon disulfide: 76u (12 + [32(2)]) C. Calcium Sulfate (S +O): 136u D. Sodium Carbonate (C +O): 106u
What is the mass percentage composition of the elements in the following compounds?
A. Fool's gold, FeS2: 56 + (32 * 2) = 120 Fe = 56 / 120 = *46.7%* S = (32 * 2) / 120 = *53.3%* B. Boric acid, H3BO3: (1 * 3) + 11 + (16 * 3) = 62 H = (1 * 3) / 62 = *4.8%* B = 11 / 62 = *17.7%* O = (16 * 3) / 62 = *77.4%*
Identify the following as combination, decomposition, replacement, or ion exchange reactions: A. NaCl(aq) + AgNO3(aq) --> NaNO3 (aq) +AgCl↓ B. H20(l) + CO2(g) --> H2CO3(l) C. 2 NaHCO3(s) --> Na2CO3(s) + H20(g) + CO2(g) D. 2 Na(s) + Cl2(g) --> 2 NaCl(s) E. Cu(s) + 2 AgNO3 (aq) --> Cu(NO3)2(aq) + 2 Ag(s) F. CaO(s) + H20(l) --> Ca(OH)2(aq)
A. Ion exchange B. Combination C. Decomposition D. Combination E. Replacement F. Combination
*Ch 10 Parallel Exercises:* Identify the following as empirical formulas or molecular formulas and indicate any uncertainty with (?):
A. MgCl2: empirical B. C2H2: molecular C. BaF2: empirical D. C8H18: molecular (#s are subscripts)
Which of the following substances is NOT a compound?
A. Water B. Table salt *C. Neon* D. Rust
Write balanced chemical equations for each of the following unbalanced reaction? A: ____SO2 + ___O2--> ____SO3 B: ____P + ____O2 --> _____P2O5 C: ____Al + ____HCl --> ____AlCl3 + ____H2 D: ___NaOH + ____H2SO4 --> _____Na2SO4 + _____H2O
A: 2, 1, 2 B: 4, 5, 2 C: 2, 6, 2, 3 D: 2,1,1, 2
What is the formula for the compound aluminum bromide?
AlBr3 (3 is subscript)
Calcium belongs to which chemical family?
Alkaline Earth Metals
What is the chemical formula if there are 2 bromide ions for each barium ion in a compound?
BaBr2 (2 is subscript)
Atoms that have eight valence electrons would tend to
Be inert
Polar covalent bonds result when the electronegativity difference between the 2 atoms in the bond is
Between 0.5 and 1.7
What is the empirical formula of butane, C4H10?
C2H5
The molecular formula of benzene, C6H6, tells us that benzene is composed of six carbon atoms and six hydrogen atoms. What is the empirical formula of benzene?
CH
What is the empirical formula of C4H8?
CH2
What products are formed from the complete reaction of hydrocarbons or carbohydrates with oxygen?
CO2 + H2O
What is the correct name for the ionic compound, CaF2?
Calcium Fluoride
You know that a chemical reaction is taking place if
Chemical bonds are formed or broken
A chemical reaction is balanced by changing (the)
Coefficient
A chemical equation is balanced by changing the
Coefficients
The iron in a scouring pad will react with oxygen in the air to form iron oxide, Fe2O3, rust. The type of reaction that is described is
Combination
To what chemical reaction class does this reaction belong? 2Mg (s) + O2 (g) --> 2MgO (s)
Combination
When carbon burns with an insufficient supply of oxygen, carbon monoxide is formed according to the follwoing equation: 2C + O2 --> 2CO. What category of chemical reaction is this?
Combination
The quantum mechanical model of the atom differs from the Bohr model in that it
Considers the electron as a wave
1 element is in the VA family of the periodic table, and a second is in the VIA family. What type of compound will these 2 elements form?
Covalent
What type of chemical bond does the sharing of a pair of electrons form?
Covalent
Which type of chemical bond is formed between 2 atoms by the sharing of 2 electrons, with one electron from each atom?
Covalent
Atoms that achieve an octet by sharing electrons form
Covalent bonds
The combination of nonmetals with nonmetals form
Covalent compounds
The element chlorine belongs to which group?
Halogens
The energy released during the formation of an ionic bond is
Heat of formation
The most active metals are found in group
I A
An empirical formula does not
Identify actual numbers of atoms in a molecule
The formation of an ionic bond
Involves a transfer of one or more electrons, results in a release of energy, helps atoms achieve a noble gas electron arrangement. ALL OF THE ABOVE
The reaction between water solutions of sodium chloride and silver nitrate produces a precipitate: NaCl(aq) + AgNO3(aq) --> NaNO3(aq) + AgCl(s). This is an example of
Ion exchange
Atoms from an element in group IIA are allowed to react with atoms from an element in group VIIA. What type of compound is likely to form?
Ionic
One element is in the IA family of the periodic table, and a second is in the VIIA family. What type of compound will the 2 elements form?
Ionic
Which type of chemical bond if formed by a transfer of electrons?
Ionic
The electrostatic attraction between positive and negative ions if calls an
Ionic bond
What types of compounds are salts, such as sodium chloride?
Ionic compounds
In an ionic compound, the metal
It is written first
"Atoms are neither created nor destroyed in a chemical reaction" is a statement of the
Law of Conservation of mass
An ion is formed when an atom of a representative element
Loses or gains electrons to satisfy the octet rule
The "fictional" element M would hypothetically form a stable ionic compound MCl2. If M were allowed to react with bromine, the resulting compound would have the formula
MBr2 (the 2 is supposed to be a subscript)
Which combination of elements results in the formation of a white crystalline solid that dissolves to form a solution that conducts electricity?
Metal and Non-metal
Which combination of elements forms crystalline solids that will dissolve in water, producing a solution of ions that can conduct an electric current?
Metal and nonmetal
"Atoms attempt to acquire an outer orbital with 8 electrons"
Octet rule
According to the quantum mechanical model, electrons exist in
Orbitals
Substances that take electrons from other substances are called
Oxidizing Agents
Propane gas burns in oxygen to produce carbon dioxide, water, and energy. The reactants in this reaction are propane and
Oxygen
A chemical bond that involves somewhat unequal sharing of electrons is called
Polar Covalent
What kind of bond has unequal sharing of bonding electrons?
Polar covalent
A covalent bond in which there is an unequal sharing of bonding electrons is a
Polar covalent bond
A solid that comes out of solution as a result of an ion exchange reaction is called a
Precipitate
Propane gas burns in oxygen to produce carbon dioxide, water, and energy. For this reaction, energy is
Released
The reaction: 2 NaI + Cl2 --> 2 NaCl + I2 is an example of
Replacement
To what chemical reaction is an example of a combination reaction belong? Fe(s) + CuSO4 (aq) --> Cu(s) + FeSO4 (aq)
Replacement
The relative arrangement of the atoms in a molecule is a
Structural formula
Because of our belief in the law of conservation of mass, it seems reasonable that
The number of atoms of reactants must equal the number of atoms of products.
An ion exchange reaction can be identified by all of the following except
The required addition of heat
What is the relationship between the energy released in burning materials produced by photosynthesis and the solar energy that was absorbed in making the materials? The energy released is
The same as the solar energy absorbed
The family or group number of the representative elements represents the
Total number of valence electrons
The electrons that participate in chemical bonding are the
Valence electrons
What determines the chemical properties of an atom?
Valence electrons
Dihydrogen monoxide is the systematic name for a compound that has the common name of
Water
Sulfur and oxygen are both in the VIA family of the periodic table. If element X combines with oxygen to form the compound X2O (2 is subscript), element X will combine with sulfur to for what compound?
X2S (2 is subscript)
Identify the charge on the following ions:
a- *Boron* Negative b- *Chlorine* Negative c- *Magnesium* Positive d-*Sodium* Positive e- *Sulfur* Negative f-*Hydrogen* Positive
From their charges, predict the periodic table family numbers for the following ions:
a- *Br1-* VII A b-* K1+* I A c- *Al3+* III A d- *S2-* VI A e- *Ba2+* II A f- *O2-* VI A
Use the periodic table to identify if the following are metals, nonmetals, or semi-conductors.
a- *Krypton* Nonmetal b- *Cesium* Metal c- *Silicon* Semiconductor d- *Sulfur* Nonmetal e- *Molybdenum* Metal f- *Plutonium* Metal
How many outer orbital electrons are found in the atoms of:
a- *Li* One b- *N* Five c- *F* Seven d- *Cl* Seven e- *Ra* Two f- *Be* Two
Write electron dot notations for the following elements:
a-*Boron* Three b-*Bromine* Seven c- *Calcium* Two d- *Potassium* One e- *Oxygen* Six f- *Sulfur* Six
Identify the period and the family in the periodic table for the following elements:
a-*Xenon* Period 5, Group VIII A b- *Potassium* Period 4, Group I A c- *Calcium* Period 4, Group II A d- *Argon* Period 3, Group VIII A e- *Bromine* Period 4, Group VII A f- *Barium* Period 6, Group II A
When atoms of non-metallic elements react with one another, they tend to seek stability by
acquiring a noble gas electron arrangement.
The fact that wavelengths of the four lines in the Balmer series fit a regular pattern was evidence supporting the idea that
electrons could only gain or lose specific amounts of energy in hydrogen atoms.