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)