Chemistry Regents Questions
B-10= 10.01 u, 19.9% B-11= 11.01 u, 80.1% Which numerical setup can be used to determine the atomic mass of the element boron?
((10.01u)(19.9)+(11.01u)(80.1))/100
Which numerical setup can be used to calculate the heat energy required to completely melt 100. grams of H2O(s) at 0 degrees C?
(100. g)(334J/g)
Br-79= 78.92u, 50.69% Br-81=80.92u, 49.31% Which numerical setup can be used to calculate the atomic mass of the element bromine?
(78.92u)(0.5069)+(80.92)(0.4931)
3CuCl2(aq)+2Al(s)->3Cu(s)+2AlCl3(aq) The oxidation number of copper changes from
+2 to 0
Compound to a 1.0-liter aqueous solution with a pH of 7.0, a 1.0-liter aqueous solution with a pH of 5.0 contains
100 times more hydronium ions
What is the gram formula mass of (NH4)3PO4
149g/mol
In which group on the periodic table would a nonmetallic element belong if atoms of this element tend to gain two electrons to complete their valence shell?
16
What is the net amount of heat released when two mole of C2H6(g) are formed from its elements at 101.3kPa and 298M?
168.0kJ
At standard pressure, the total amount of heat required to completely vaporize a 100-gram sample of water at its boiling point?
2.26 x 10^5 J
At which temperature will Hg(l) and Hg(s) reach equilibrium in a closed system at 1.0 atmosphere>
232K
How many pairs of electrons are shared between the nitrogen atoms in a molecule of N2?
3
What is the amount of heat released by 1.00 gram of liquid water at 0 degrees celsius when it changes to 1.00 gram of ice at 0 degrees celsius?
334J
Which sample of copper has atoms with the lowest average kinetic energy? ( 10g at 45C, 30g at 25C, 20g at 35C, 40g at 15C)
40g at 15C
What is the number of moles of CO2 in a 220.-gram sample of CO2 (gram-formula mass=44g/mol)
5.0 mol
When a sample of Mg(s) reacts completely with O2(g), the Mg(s) loses 5.0 moles of electrons. How many moles of electrons are gained by the O2(g)?
5.0 moles
What is the number of electrons shared between the atoms in a molecule of nitrogen?
6
Based on table F, which equation represents a saturated solution having the lowest concentration of Cl- ions? (AgCl(s)<->Ag+(aq)+Cl-(aq), NH4Cl(s)<->NH4+(aq)+Cl-(aq), KCl(s)<->K+(aq)+Cl-(aq))
AgCl(s)<->Ag+(aq)+Cl-(aq)
Which general trends in atomic radius and electronegativity are observed as the elements in Period 3 are considered in order of increasing atomic number?
Atomic radius decreases and electronegativity increases
C2H2, C3H4, C4H6, C4H10 Which hydrocarbon is saturated?
C4H10
Which compound is classified as an ether? (CH3CHO, CH3COCH3, CH3OCH3, CH3COOCH3)
CH3OCH3
Which process occurs in an operating voltaic cell?
Chemical energy is converted to electrical energy
Which ion is most easily reduced? (Zn2+, Mg2+, Co2+, Ca2+)
Co2+
Which metal reacts spontaneously with Sr2+ ions? (Ca(s), Co(s), Cs(s), Cu(s))
Cs(s)
Which ionic equation represents a spontaneous reaction that can occur in a voltaic cell? (Cu(s)+Zn(s)->Cu2+(aq)+Zn2+(aq), Cu(s)+Zn2+(aq)->Cu2+(aq)+Zn(s), Cu2+(aq)+Zn(s)->Cu(s)+Zn2+(aq), Cu2+(aq)+Zn2+(aq)->Cu(s)+Zn(s))
Cu2+(aq)+Zn(s)->Cu(s)+Zn2+(aq)
Molar concentrations of hydronium ion, H3O+, in four different solutions. Solution A-.1, B-.01, C-.001, D-.0001 Which solution has the highest pH?
D
A mixture consists of sand and an aqueous salt solution. Which procedure can be used to separate the sand, salt, and water from eachother?
Filter out the sand, then evaporate the water
Which group on the Periodic table has two elements that exist as gases at STP?
Group 17
H-H, O=C=O, H-O-H Which formula represents a nonpolar molecule containing polar covalent bonds?
H-O-H
HF-molar mass=20.01g/mol boiling point=293 K, HCl- mm=36.46 bp=188, HBr- mm=80.91 bp=207, Hl mm=127.91 bp=237 Which compound has the strongest intermolecular forces?
HF
Which Lewis dot diagram represents the bonding in potassium iodide?
K+[I]- (8 dots around I)
Which metal is most easily oxidized? (Ag, Cu, Co, Mg)
Mg
Which balanced equation represents a redox reaction? (Mg+Cl2->MgCl2, CaO+H2O->Ca(OH)2, HNO3+NaOH->NaNO3+H2O, NaCl+AgNO3->AgCl+NaNO3)
Mg+Cl2->MgCl2
According to Table I, which equation represents a change resulting in the greatest quantity of energy released? (2C(s)+3H2(g)->C2H6(g), 2C(s)+2H2(g)->C2H4(g), N2(g)+3H2(g)->2NH3(g), N2(g)+O2(g)->2NO(g))
N2(g)+3H2(g)->2NH3(g)
At 101.3 kPa and 298K, a 1.0-mole sample of which compound absorbs the greatest amount of heat as the entire sample dissolves in water? (LiBr, NaCl, NaOH, NH4Cl)
NH4Cl
Based on Table I, which compound dissolves in water by an exothermic process? (NaCl, NaOH, NH4Cl, NH4NO3)
NaOH
Which pair represents two forms of an element in the same phase at STP but with different structures and different? (O2(g) and O3(g), I2(s) and I2(g), H2(g) and Hg(g), H2O(s) and H2O(l))
O2(g) and O3(g)
C4H10+Cl2->C4H9Cl+HCl Which type of reaction is represented by the equation?
Substitution
Which statement describes the charge distribution and the polarity of a CH4 molecule?
The charge distribution is symmetrical and the molecule is nonpolar
BaSO4(s)<-H2O->Ba2+(aq)+SO42-(aq) What occurs when Na2SO4(s) is added to this system, increasing the concentration of SO42-(aq)?
The equilibrium shifts to the left, and the concentration of Ba2+(aq) decreases
A sample of water is boiling as heat is added at a constant rate. Which statement describes the potential energy and the average kinetic energy of the water molecules in this sample?
The potential energy increases and the average kinetic energy remains the same.
Which phrase describes a compound that consists of two elements?
a substance in which the elements are chemically combined in a fixed proportion
2SO2(g)+O2(g)<->2SO3(g)+heat Which change causes the equilibrium to shift to the right?
adding more O2(g)
Which nuclear emission has the least penetrating power and the greatest ionizing ability?
alpha particle
Which functional group contains a nitrogen atom and an oxygen atom?
amide
When comparing the voltaic cells to electrolytic cells, oxidation occurs at the...
anode in both types of cells
According to the kinetic molecular theory, the particles of an ideal gas
are separated by great distances, compared to their size
As the elements in Period 2 of the Periodic Table are considered in order from left to right, which property generally decreases?
atomic radius
The temperature of a sample of matter is a measure of the
average kinetic energy of the particles of the sample
Distillation is a process used to separate a mixture of liquids based on different
boiling points
Which compound is saturated? (butane, ethene, heptene, pentyne)
butane
Which element has chemical properties that are most similar to potassium? (calcium, cesium, nitrogen, sulfur)
cesium
Which type of organic reaction produces both water and carbon dioxide?
combustion
As a result of the gold foil experiment, it was concluded that an atom
contains a small, dense nucleus
The ratio of the mass of the U-238 to the mass of Pb-206 can be used to
date geological formations
A 10.0-gram sample of nitrogen is at STP. Which property will increase when the sample is cooled to 72K at standard pressure?
density
Carbon monoxide and carbon dioxide have
different chemical properties and different physical properties
At 1 atm, equal masses of H2O(s), H2O(l), and H2O(g) have
different volumes
What phase represents the phase change solid->gas?
endothermic physical change
H2+energy->H+H What occurs as bonds are broken in one mole of H2 molecules during this reaction?
energy is absorbed and two moles of unbonded hydrogen atoms are produced
A reaction between an alcohol and an organic acid is classified as
esterification
The discovery of the electron as a subatomic particle was a result of
experiments with cathode ray tubes
Which term represents the sum of the atomic masses of the atoms in a molecule?
formula mass
During which two processes does a substance release energy? (freezing and condensation, freezing and melting, evaporation and condensation, evaporation and melting)
freezing and condensation
Which list of nuclear emissions is arranged in order from the greatest penetrating power to the least penetrating?
gamma ray, beta particle, alpha particle
Which value is defined as the difference between the potential energy of the products and the potential energy of the reactants during a chemical change?
heat of reaction
Which elements can react to produce a molecule compound?
hydrogen and sulfur
Which term identifies a type of intermolecular force?
hydrogen bonding
PCl5(g)+energy<->PCl3(g)+Cl(g) Which change will cause the equilibrium to shift to the right? (adding a catalyst, adding more PCl3(g), increasing the pressure, increasing the temperature)
increasing the temperature
Compared to the mass and the penetrating power of an alpha particle, a beta particle
less mass and greater penetrating power
Trial 1-50 mL, .2M, .1g, 48s Trial 2-50mL, .4M, .1g, ?s Compared to trial 1, what is the expected reaction time for trial 2 and the explanation for the result?
less that 48s, because there are more effective particle collisions per second
Paper chromatography can separate the components of a mixture of colored dyes because the components have differences in
molecular polarity
Can an addition reaction have double bonds?
no
Is a molecular compound a good conductor?
no
Which phrase describes the molecular polarity and distribution of charge in a molecule of carbon dioxide?
nonpolar and symmetrical
At STP, which substance has metallic bonding? (ammonium chloride, iodine, barium oxide, silver)
silver
Which term identifies a factor that will shift a chemical equilibrium?
temperature
The activation energy on a graph is
the potential energy of the reactants to the vertex of the curve
The isomers butane and methylpropane have
the same molecular formula and different properties
Which electron shell contains the valence electrons of a radium atom in the ground state?
the seventh shell
A solid sample of a compound and a liquid sample of the same compound are each tested for electrical conductivity. Which test conclusion indicates that the compound is ionic?
the solid is a poor conductor, and the liquid is a good conductor
Two hydrogen atoms form a hydrogen molecule when
the two atoms collide with sufficient energy to form a bond
Which statement describes the particles of an ideal gas, based on the kinetic molecular theory? (There are attractive forces between the particles, the particles move in circular paths, the collisions between the particles reduce the total energy of the gas, the volume of the gas particles is negligible compared with the total volume of the gas)
the volume of the gas particles is negligible compared with the total volume of the gas
Is an ionic compound a good conductor?
yes
What graph shows the relationship between pressure and Kelvin temperature for an ideal gas at constant volume?
|/_ (pressure y axis, temperature x axis)