Chem final
In writing a chemical equation that produces hydrogen gas, the correct representation of hydrogen gas
H2
A compound empirical formula is HO. If the formula mass is 34 amu, what is the molecular formula
H2O2
The most reactive group of the nonmetals is the
Halogens
Compared with ionic compounds, molecular compounds
Have Lower melting points
The Pauli exclusion principle states that no two elections in the same atom can
Have the same set of quantum numbers
No polar covalent bonds are not common because
One atom usually attracts electrons more strongly then the other
Which of these measurements has been expressed to four significant figures
30.00mm
The mass of 2.0 mol of oxygen atoms is
32 g
How many atoms of fluorine are present in a molecule of carbon tetrafluoride
4
The number of significant figures in the measurement 2010 cm is
4
The density of aluminum is 2.70 g/cm^3. What is the mass of a solid piece of aluminum with a volume of 1.50 cm^3
4.05 g
For an electron in an atoms to change from the ground state to an excited state
Emery must be absorbed
A formulae that shows the simplest whole number ratio of the atoms In a compound is the
Empirical formula
Magnesium bromide + chlorine yields
MgCl2 and Br2
A neutral group of atoms held together by covalent bonds is
Molecule
The person whose work led to a periodic table based on increasing atomic number was
Moseley
Chemists once theorized that a molecule that contains a single bond and a double bond split its time existing as one of these 2 structure. This is known as
Multiple bonding
A compounds empirical formula is N2O5. If the formula mass is 108 amu what is the molecular formula
N2O5
Under suitable conditions, roughly what proportion of all chemical reactions are reversible
Nearly all
The first member of the noble gas family, whose highest energy level consists of an octet of electrons is
Neon
If 2 covalently bonded atoms are identical, the bond is
No polar covalent
What group of elements satisfied the octet rule without forming compounds
Noble gas
Argon, krypton and xenon are
Noble gases
A chemical formula includes the symbols of the elements in the compound and subscripts that indicate
Number of atoms or ions of each element that are combined in the compound
The periodic law states that the physical and chemical properties of elements are periodic functions of their atomic
Numbers
A volume of 1 milliliter is equivalent to
1 cubic centimeter
What is the oxidation numbe of hydrogen in H2O
3
Which of the following is not an example of a molecular formula
B
What are shared in a covalent bond?
Electrons
In an equation, the symbol for a substance in water solution is followed by
(aq)
What is the oxidation number for hydrogen in KH
-1
The density of pure diamond is 3.5 g/cm^3. What is the volume of a diamond with a mass of 0.25g
0.071 cm^3
Which of these measurements has been expressed to three significant figures
0.202g
The liter is defined as
1000cm^3
For the reaction represented by the equation 2H2 + O2 > 2H20, how many mol of water can be produced from 6.0 mol of oxygen
12 mol I
What is the percentage composition of Ch4
13.6 % C, 86.4 % F
What is the formula mass of (NH4)2SO4
132.16 amu
Chlorine has atomic number 17 and mass number 35. It has
17 protons, 17 electrons and 18 neutrons
Phosphorus 33 contains
18 neutrons
A sample of gold has a mass of 96.5 g and a volume of 5.00 cm^3. The density of gold is
19.3 g/cm^3
In the reaction represented by the equation N2 + 3H2 > 2NH3, what is the mole ratio of nitrogen to ammonia
1:2
What is the electron configuration for nitrogen, atomic number 7?
1s^2 2s^2 2p^3
The measurement o.020 L is the same as
2.0 x 10^-2
For the reaction represented by the equation C + 2H2 > CH4, how many miles of hydrogen are required to produce 10 mol of methane, CH4
20 mol
Neon 22 contains 12 neutrons. It also contains
22 protons
An aluminum isotope consists of 13 protons, 13 elections, and 14 neutrons. It's mass number is
27
The major difference between a 1s orbital and a 2s orbital is that
2s orbital can hold more electrons
The number of possible different orbital shapes for the 3rd energy level is
3
The number of significant figures in the measured value 0.032 g is
3
The number of significant figures in the measurement 0.000305 kg is
3
In the equation 2KClO3 > 2KCl + 3O2, how many moles of oxygen are produced when 3.0 mol of KClO3 decompose completely
4.5 mol
What is the percentage composition of CO
43, 57
What is the percentage composition of CuCL2
43.27, 52.73
In the reaction represented by the equation 2Al2O3 > 4Al + 3O2, what is the mole ratio of aluminum to oxygen
4:3
The number of orbitals for the d sub level is
5
The mass of 1 mol of chromium is
51.996 g
A sample of tin contains 3.01 * 10^23. The mas of the sample is
59.3 g
What is the oxidation number of sulfur in H2SO4
6
How many oxygen atoms are there in 0.500 mol of CO2
6.02 * 10^23
the number of atoms in 1 mol of carbon is
6.022 * 10^23
How is the measurement 0.000065 written is scientific notation
6.5 x 10^-5
The molar mass of CCL4 is 153.81. How many grams of CCL4 are needed to have 5.000 mol
769.0
In a mole of fluorine the 2 shared electrons give each other Florine atom how many election in the outer energy level
8
In drawing a Lewis structure, each nonmetal atom except hydrogen should be surrounded by
8 electrons
Carbon-14, the radioactive nuclide used in dating fossils, has
8 neutrons
An orbital that can never exist according to the quantum description of the atom is
8s
How many molecules are there in 5.0 g of methyl alcohol, CH3OH
9.4*10^22
The mass of a sample containing 3.5 mol of silicon atoms is approximately
98 g
A mixture is
A blend of any two or more kinds of matter, as long as each maintains its own unique properties
A chemical formula written over the arrow in a chemical equation signifies
A catalyst for the reaction
It is easy to determine whether a substance is a metal if the sunstance is
A good electrical and heat conductor
A compound is
A substance, made of two or more atoms that are chemically bonded, that can be broken down into simpler, stable substances
Which of the following burns most slowly?
A large lump of coal
When a solid produced by a chemical reaction separated from the solution it is called
A precipitate
A polar molecule contains
A region of positive charge and a region of negative charge
A homogeneous mixture is also called
A solution
A measurement that closely agrees with an accepted value is best described as
Accurate
The minimum energy required for an effective collision is called
Activation energy
The group of soft, silvery, reactive metals, all of which have one electron in an s orbital, is known as the
Alkali metals
Which of the following affect reaction rate
All of the above
Metals are malleable because the metallic bonding
Allows one plane of ions to slide past another
According to the law of conservation of mass, the total mass of the reacting substances is
Always equal to the total mass of products
A solid substance is
Always the same shape regardless of its container
What is removed when the ionization energy is supplied to an atom of an element?
An electron
According to the quantum theory of an atom, in an orbital
An electrons position cannot be known precisely
A positive ion is called a
Anion
Compared to the alkali metals, the alkaline-earth metal
Are less reactive
All atoms of the same element have the same
Atomic number
One half the distance between the nuclei of identical atoms that are bonded together is called the
Atomic radius
Dalton incorporated the law of conservation of mass into his atomic theory by asserting that
Atoms are indivisible
Molar mass
Both A and b
At equilibrium
Both the forward and reverse reactions continue
A nonmetal is usually
Brittle
Which of the following is not a physical change?
Burning
The molecular formula for a vitamin C is C6H8O6. What is the empirical formula
C3H4O3
Of the following molecular formulas for hydrocarbons, which us an empirical formula
CH4
The word equation solid carbon + oxygen gas > carbon dioxide gas + energy, represent a chemical reaction because
CO2 has chemical properties that differ from those of C and O
What is the formula for the compound formed by calcium ions and chloride ions
CaCL2
A negative ion is known as
Cation
The value of the equilibrium constant for the reaction
Changes with temperature
Which branch of Chem studies reaction rates
Chemical kinetics
Which attempts to explain chemical reactions and physical interactions of molecules
Collision theory
The nucleus of an atom has all of the following characteristics except that it
Contains nearly all the atoms volume
What is the correct Lewis structure for hydrogen chloride?
D
The equation AX > A+ X
Decomposition
The reaction represented by the equation 2 HgO > 2Hg + O2
Decomposition
The reaction represented by the equation 2KCLO3 > 2KCL + 3O2 is a
Decomposition
In what kind of reaction does a single compound produce 2 or more similar substances
Decomposition reaction
Which of the following is and intensive property of matter?
Densiry
A measure of the quantity of matter is
Density
The quantity of matter per unit volume is
Density
In what kind of reaction does one element replace a similar element in a compound
Displacement
What two processed are at equilibrium in a saturated sugar solution
Dissolving and crystallization
The equation AX + BY > AY + BX
Double replacement
The reaction represented by the equation Pb(NO3)2 + 2KI > PbI2 + 2KNO3 is a
Double replacement
When an electron is acquired by a neutral atom, the energy change is called
Electron affinity
A measure of the ability of an atom in a chemical compound to attract electrons from another atom in the compound is called
Electronegativity
Most of the volume of an atom is occupied by the
Electrons
According to the law of conservation of mass. When sodium, hydrogen and oxygen react to form a compound, the mass of the compound is _____ the sum of the masses of the individual elements
Equal to
Bohrs theory helped explain why
Excited hydrogen gas gives off certain colors of light
The element that has the greatest electro negativity is
Fluorine
A theory is best described as a
Generalization that explains a body of known facts or phenomena
A chemist obtained the values 5.2246 g, 5.2353 g, and 5.2501 g for the mass of a sample
Good precision
Accros a period in the periodic table, atomic radii
Gradually decrease
Which of the following is an example of a heterogeneous mixture?
Granite
If electrons in a atom have the lowest possible energies the atom is in the
Ground state
The vertical columns on the periodic table are called
Groups
the liquid state of matter can be described as
Having a definite volume but not a definite shape
If a mixture is not uniform throughout, it is called
Heterogeneous
The shiny appearance of a metal is most closely related to the metals
Highly mobile valence electrons
Ionic compounds are brittle because the strong attractive forces
Hold the layers in relatively fixed positions
If a mixture is uniform in composition, it is said to be
Homogeneous
The reason the boiling point of water is higher than the boiling point of hydrogen sulfide is partially explained by
Hydrogen bonding
A statement that can be tested experimentally is a
Hypothesis
Valence electrons are those s and p electrons
In he highest every level
The B-F bond in BF is
Ionic
The greater the electronegativity difference between 2 bonded atoms, the greater the percentage of
Ionic character
The energy required to remove an electron from an atom is the atoms
Ionization energy
At equilibrium, the total amount of the products
Is always equal to the total amount of reactants
What happens to the energy in a substance when it changes state?
It changes form, but it's neither destroyed nor increased
How does the value of K show that a reaction reaches equilibrium very quickly
K is zero
What is the empirical formula for a compound that is 31.9 % potassium, 28.9 % chlorine and 39.2 % oxygen
KClO3
Matter includes all of the following except
Light
A state of matter in which a material has no definite shape but has a definite volume is ___ state
Liquid
If a material can be shaped or extended by physical pressure, such as hammering, which property does the material have
Malleability
All of the following are examples of units except
Mass
The periodic law school states that the properties of elements are periodic functions of their atomic numbers. What determines the position of each element in the periodic table
Mass number
The total number of protons and neutrons in the nucleus of an atom is its
Mass number
Isotopes are atoms of the same element that have different
Masses
The idea of arranging the elements in the periodic table according to their chemical and physical properties is attributed to
Mendeleev
Malleability and ductility are characteristic of substance with
Metallic bonds
Elements in which the d-sub level is being filled have the properties of
Metals
The pair of elements that forms a bond with the least ionic character is
Mg and Cl
In the chemical equation 2Mg + O2 > 2MgO
Mg represents the product magnesium
Predict the product of the reaction represented by the following equation MgO + CO2 >
MgCO3
When determining the size of an atoms by measuring the distance between bonded, identical, adjacent, nuclei, the radius of an atom is
One half the distance between nuclei
Multiple covalent bonds may occur in atoms that contain carbon, nitrogen or
Oxygen
What is the empirical formula for a compound that is 43.6% phosphorus and 56.4% oxygen
P2O5
Most chemical bonds are
Partially ionic and partially covalent
A horizontal row of blocks in the periodic table is called
Period
All known chemical elements are organized into groups based on similar chemical properties in the?
Periodic chart
The horizontal rows on the periodic table are called
Periods
The periodic table
Permits the properties of element to be predicted before the element is discovered
A quantum of electromagnetic energy is called an
Photon
If the atoms that share electrons have an unequal attraction for the electrons, the bond is called
Polar
The atomic number of oxygen, 8, indicates that there are 8
Protons in the nucleus of an oxygen atom
Nitrogen monoxide and oxygen, both colorless gases, form a red-brown gas when mixed. Nitrogen monoxide and oxygen are called the
Reactants
A very low value of K indicates that
Reactants are favored
The radius of an atom extends to the outer edge of the
Region occupied by the nucleus
As the mass number of an elements isotopes of an element increases, the number of protons
Remains the same
A numerical result is said to have a good precision if
Repeated measurements agree closely
A reaction in which products can react to re-form reactants is
Reversible
An active metal and a halogen react to form an
Salt
Metalloids are often
Semiconductors
Bonding in molecules or ions that cannot be correctly represented by a single Lewis structure is
Single bonding
The equation A + BX > AX + B
Single replacement
The reaction represented by the equation Mg + 2 HCL > H2 + MgCL2 is a
Single replacement
The reaction represented by the equation Cl2 + 2KBr > 2KCl + Br2 is a
Single-replacement
The Lattice energy is a measure of the
Strength of an ionic bond
The equation A + X > AX
Synthesis
In what kind of reaction do two or more substances combine to form a new compound?
Synthesis reactikn
What was the radioactive elements with atomic number 90 to 103 called
The actinides
The statement that an electron occupied the lowest available energy orbital is
The aufbau principle
If the lattice energy of. Compound A is greater than that of compound B
The bonds in compound A are stronger than the bonds in compound B
Which of these statements about density is true
The density of an object depends on the force of gravity
At equilibrium
The forward reaction rate is equal to the reverse reaction rate
Which of the following observations is quantitative
The liquid is cloudy
An atom is electrically neutral because
The number of protons and electrons are equal
The statement that no two electrons in the same atom can have the same four quantum numbers is
The pauli exclusion principle
If the surface are of reactants is larger
The reaction rate is generally higher
If the concentration of reactants is higher
The reaction rate is generally lower
An atom is
The smallest unit of matter that maintains its chemical identity
Which of the following observations is qualitative
The solid had a mass of 23.4 grams
When density is measured
The units are always kg/m^3
A plausible explanation of a body of observed natural phenomena is a scientific
Theory
Atoms naturally move
Toward low potential energy
Noble gases are in group 18, and are best known because they are
Un- reactive
The only pure substance listed below is
Vinegar
Which of the following is an extensive property of matter?
Volume
The distance between 2 successive peaks on adjacent waves is its
Wavelength
The forces of attraction between molecules in a molecular compound are
Weaker than the forces among formula units in ionic bonding
A change in the force of gravity on an object will affect its
Weight
What us the formula for zinc fluoride
ZnF2
In determining the atomic mass of elements the standard is the
c-12 atom
The symbols for units of length in order from largest to smallest are
km, m, cm, mm