Gen chem 1-10 practice exam questions

Zero order kinetics the y -axis units are

concentraion, slope is -k

To separate a homogeneous mixture of salt water, which of the following pieces of laboratory equipment is necessary?

condenser

Oxoacids are acids that

contain oxygen

Which of the following changes will result in the greatest increase in solubility of O2 gas in water?

Increase pressure of the gas and decrease temperature of the solution

only temperature can change the

Ka.

The solubility of solid AgCl in water was found to be 1.34 x 10-5 mol/L and the solubility of solid AgBr in water was 7.07 x 10-7 mol/L. Which of the following conclusions can be made?

Ksp is solubility The higher the molar solubility is, the larger the Ksp value will be. AgCl, with a molar solubility of 1.34 x 10-5 has a higher Ksp than AgBr.

What is the concentration of Pb2+ at equilibrium if the Ksp of PbCl2 equals 1.8 x 10-5 in an aqueous solution of pure water?

Ksp= (Pb 2+)(cl-)^2

Species that can accept an electron pair are

Lewis acids

species that can donate an electron pair are

Lewis bases.

Which of the following descriptions accurately describes a metal?

Metals tend to form cations in aqueous solution.

Strong bases include

Mg(OH)2 Ca(OH)2 Sr(OH)2 Ba(OH)2

why along the same period, a non-metal has a smaller atomic radius than a metal?

Non-metals have a higher effective nuclear charge

The formula for osmotic pressure is:

Pressure= iMRT i is the # of ions M is molarity R is 0.082 T is temp in K

Kc is larger when the reaction shifts to the

RIGHT

What are the molecular shape and the hybridization of the central atom in phosphorus pentachloride?

Trigonal bipyramidal, sp3d

A fixed sample of an ideal gas occupies a volume of 1.2 L at 30°C and 1.0 atm. What volume will the gas occupy if the temperature is increased to 60°C at constant pressure?

Use V1/t1=v2/t2 Convert temp into K

If KCl is added to distilled water, which of the following properties would decrease in value?

Vapor pressure of the solution

the dense particles within an atomic nucleus.

a nucleon

A state function

a property whose value does not depend on how that state was achieved. Enthalpy, volume, mass and Gibbs free energy are all state functions.

positron emission

a proton converts into a neutron and emits a positron

isoelectronic series

a series of atoms, ions, or molecules having the same number of electrons

In a disproportionation reaction

a substance is simultaneously oxidized and reduced, giving two different products.

ideal gases

a theoretical gas that conforms to kinetic molecular theory and behaves as described by the ideal gas law, PV = nRT

Filtration

an effective technique to separate a solid from a liquid.

What is an activated complex?

an unstable arrangement of atoms that forms momentarily at the peak of the activation-energy barrier

Oxidation occurs at the Reduction occurs at the

anode cathode

reaction intermediates never

appear in rate equations.

The standard cell potential of a voltaic cell is:

ecell= E reduction (2)-E reduction (1)

A non-spontaneous electrochemical cell is an

electrolytic cell

all transition metals are more

electronegative than alkali metals

the forward reaction never has the same

entropy as the reverse reaction

With increasing temperatures, which of the following occurs?

entropy increases

At increasing temperatures, an exothermic reaction at equilibrium will proceed at a

faster rate while its Kc decreases

The energy of a photon is directly proportional to which of the following?

frequency

Which type of nuclear decay will NOT change the atomic number of the element?

gamma decay

Deposition

gas to solid

A graduated cylinder or pipet are common

glassware for accurately measuring volumes of liquid.

weak acid/strong base has a pH of

greater than 7

Weak acid and strong base will have a pH

greater than 7 at the equivalence point.

sublimation will involve the

greatest increase in enthalpy and entropy.

Enthalpy (ΔH) refers to

heat energy.

If electron affinity is low, and ionization energy is low, atomic radii would be

high for both atoms.

Network covalent bonds have

high melting poing hard, and are non conductive

ionic bonds have

high melting point are brittle and hard

A real gas is most likely to exhibit ideal gas behavior under which of the following conditions?

high temperature and low pressure

Gamma rays have the

highest energy and shortest wavelengths

while decreasing/increasing temperature only results in

horizontal movement of the substance.

The group 1 elements, alkali metals, react vigorously with water to produce

hydrogen gas.

The concentration of products will not affect the rate of an

irreversible reaction.

The compound losing electrons (ie, becoming more positive)

is getting oxidized.

The compound gaining electrons (ie, becoming more negative)

is getting reduced.

Electron affinity

it increases as you go up in a group (column) and right in a period (row).

The titrant is a

known solution that is added in order to find the titrant's concentration

Water molecules in an aqueous solution will have the strongest interactions with ions with which of the following characteristics?

large charge and small size

Kc is smaller when the reaction shifts the

left

weak base and strong acid has a pH of

less than 7

Weak base and strong acid will have a pH

less than 7 at the equivalence point

in an exothermic reaction, the forward activation energy is

less than the reverse activation energy.

Evaporation is the transition at the surface of a

liquid from liquid to gas

In equilibrium expressions no

liquids or solids included in the equilibrium constant expression.

first order reaction y-axis units are

ln concenetration, slope is -k

conjugate base

lost proton

molecular bonds have

low melting points and are non conductive

If a liquid is found to have weak intermolecular forces, then that liquid will generally have a

low viscosity

The forward reaction has a

lower activation energy.

higher vapor pressure means

lower boiling point and weaker intermolecular forces

Radio waves have the

lowest energy and longest wavelengths.

Paramagnetic means attracted to

magnetic fields. They have at least one unpaired electron in their orbitals.

For multiplying and dividing, the number of significant figures is determined by the

measurement with the fewest number of significant figures.

barometer

measures air pressure

electronic balance

measures mass

thermometer

measures temperature

Decreasing the pressure decreases the boiling point and increases the

melting point

Adding more solute will increases

molarity,ostomitic pressure, molality and boiling pressure.

Compounds are

molecules composed of two or more bonded different elements that exist in fixed proportions.

the more sponatous reaction is the one that is the

most positive and the strongest reducing agent along with being oxidized

A reaction is spontaneous if ΔG is

negative

As something becomes more organized (from a gas → liquid → solid), ΔH and ΔS is

negative.

B decay for b emission results in

neutron to proton

Isotopes have the same number of protons, but different numbers of

neutrons

Gas to solid is

non spontaneous

CF4 has polar bonds but is

non-polar overall.

Mass defect in nuclei is a direct result of the conversion of some nuclear mass to energy, called

nuclear binding energy.

x decay can be used to result in

nutreon to proton

As you go down a column in the periodic table, size increases because

of the addition of another electron shell and electron shielding.

Entropy (ΔS) refers to the state of

order or disorder.

losing electrons from left to right makes it more

organized

The titrand is the

original solution with an unknown concentration

strongest reducing agent is the one that is getting

oxidized if you flip the equation completely

The solubility of a gas is directly proportional to its

partial pressure

Heat and work are examples of

path (non-state) functions.

nitrogen can bond to fewer atoms than

phosphorus

Which of the following pieces of equipment would be best to measure and transfer 8.7 mL of a solution from an Erlenmeyer into a test tube?

pipet

As something becomes less organized (from a solid → liquid → gas), ΔH and ΔS is

positive.

A path function is a

property in which the process matters. Path functions depend on the transition or change of the state. Heat and work are examples of path (non-state) functions.

a base

proton acceptor

a base is defined as a

proton acceptor.

An acid is defined as a

proton donor

an acid

proton donor

B decay(positron emission) and electron capture both result in

proton to neutron

Crystallization is used to

purify solid compounds on the basis of differences in solubility.

Which of the following scenarios best illustrates Boyle's Law?

pushing a balloon

ΔH and ΔS are positive, this reaction will be ____________ at a high temperature.

spontaneous

Enthalpy, volume, mass and Gibbs free energy are all

state functions.

Weak bases have a

strong conjugate acid.

Weak acids have a

strong conjugate base.

Hydrogen bonds are

stronger intermolecular forces. This liquid would not evaporate as easily.

one with the highest pKb is the one with the

strongest base

The bond length between two atoms is equal to the

sum of the atomic radii of the two atoms.

What is the rate constant of a first-order reaction with a half-life of 5 minutes?

t 1/2= ln(2)/k Convert to seconds then do 300s=.693/k which is K= .693/300s Ln(2) is constant .693

half life of a first order reaction

t1/2=0.693/k

Entropy increases with

temperature

the only thing that can change Kc is

temperature, as Kc increases temp decreases.

Double bonds are stronger

than single bonds, and triple bonds are stronger than double bonds.

Oxoacids are acids

that contain oxygen

As the atoms become larger with a greater mass,

the Van der Waals forces increase, and boiling point rises.

As PKA goes down

the acid strength goes up

The group 2 elements, alkaline earth metals, also react with water. However, they do not react as vigorously as

the alkali metals.

Pressure is directly proportional to

the amount of the gas sample. (Moles)

In an electrolytic cell

the cathode is the negative electrode

The more moles a gas has ,

the higher its entropy.

the weaker the intermolecular force,

the higher the volatility.

Adding acid to water ensures that

the large volume of water will absorb the heat produced and prevents splashing.

The higher the molar solubility is,

the larger the Ksp value will be.

In an ionic compound, which element is losing electrons?

the metal

what occurs if T is increased for an Endothermic Reaction or T is decreased for an Exothermic reaction.

the reaction shifts to the right

the energy diagram of a reversible exothermic reaction says that

the reverse reaction has a larger than the forward reaction.

The smaller the atomic radii,

the smaller the bond length

the weaker the acid the

the stronger the conjugate base

boiling point

the temperature at which the vapor pressure of the liquid equals the surrounding pressure

Distillation

used to separate two liquids in a solution

Decreasing/increasing pressure only results in

vertical movement of the substance

A spontaneous electrochemical cell is a

voltaic or galvanic cell.

The group 1 elements, alkali metals, react vigorously with

water to produce hydrogen gas.

Always add acid to

water, never the other way around.

HF is a

weak electrolyte.

London dispersion forces are

weak intermolecular forces that arise from instantaneous dipoles in molecules without dipoles

sublime

when a compound has a vapor pressure higher than atmospheric pressure

Weak electrolyte

will have the lowest amount of ions in solution and will have the lowest electrical conductivity.

The reaction with the lowest activation energy, the difference in energy between the reactant and the transition state or the highest point along the reaction path,

will occur the fastest.

As the temperature increases, the disorder among the particles increases as solids begin to melt and liquids begin to vaporize.

.

Describe the reaction below: PCl3(g) + Cl2(g)→ PCl5(g) ; ΔHf = -87.9 kJ/mol

(ΔG<0) bc the number is negative, H will be less than 0

monoatomic gases

*noble gases* are monoatomic gases: He, Ne, Ar, Kr, Xe, Rn

Beta Decay

0/-1 e

The units are M·s-1, or M1·s-1. To find the reaction order, add the exponents and take the absolute value:

1 + (-1) = 0 This is a zero-order reaction.

second order reaction, y-axis is

1/con, slope is k

the third energy level can hold

18 electrons

first energy level can hold

2 electrons

A sample of an ideal gas at 25oC and 1 atm has a volume of 1.2 L. What will be the volume of the same sample of gas at 0.5 atm pressure and 25oC?

2.4, bc if pressure is decreased by half, volume will double.

Uranium-235 is a radioactive nuclide that decays by alpha emission. What is the product of decay of Uranium-235?

235U92-----> 4he2+231th90

the fourth energy level can hold

32 electrons

Alpha Decay

4/2 He

Strong acid/strong base has a pH of

7

Strong acid and strong base will have a pH of

7 at the equivalence point.

the second energy level can hold

8 electrons

Boyle's Law

A principle that describes the relationship between the pressure and volume of a gas at constant temperature

colligavtive property

A. Vapor pressure B. Freezing point C. Osmotic pressure D. Boiling point

In which instance is a gas most likely to behave ideally?

At high temperatures and low pressures, because the molecules are far apart and not likely to interact.

What is the temperature at which 64 g of O2 will occupy a volume of 8.2 L at 760 Torr?

Convert O2 to moles Then use ideal gas pressure equation which is T=PV/nR P is 1 atm since it was not stated V is volume N is moles of O2 and R is constant .082

The temperature dependence of spontaneity is given by:

Delta G= Delta H- Temp Delta S

The second law of thermodynamics deals with the spontaneity of the change of matter in terms of entropy (S). A change is spontaneous if

Delta S surrounding + Delta S system is more than 0

A standard voltaic cell is constructed using Cu metal in 1.0 M Cu(NO3)2(aq) and an unknown metal in a 1.0 M solution of its nitrate salt. The cell voltage is 0.47 V when the Cu half-cell is the cathode. What is the standard reduction potential of the unknown metal? EoCu2+/Cu = 0.34 V

Ecell= E red + E ox Plug values in .47v=.34+E ox Eoc=.13v Turn into a negative for Ered= -.13V

ΔH

Enthlapy change

A spontaneous process is one where ΔG < 0, or when ΔH < 0 and ΔS > 0 according to the equation

G=H-Ts

The enthalpy change can be calculated from bond energies using the following equation:

H= H bond broken - H bonds formed H bond is the rectants and H bond formed is the products

Strong acids are

HCl, HBr, HI, HNO3, H2SO4, HClO4

If pressure is decreased while temperature is constant, there are three possibilities

Solid to gas: Sublimation Liquid to solid: Crystallization Liquid to gas: Vaporization

Why does a nucleus weigh less than the sum of its neutrons and protons?

Some of the nucleus's mass gets converted into energy to hold the nucleus together

A change is spontaneous if

Surrounding + System is less than 0

1 mol of HNO3 is dissolved in 54.0 grams of H2O. What is the mole fraction of HNO3?

The equation for mole fraction is: mol fraction= mol of component/ total mol of all compounds Convert to moles than do 1 mole hno3/1mol hno3+ 3 mol of h2o

Which of the following solutions has the lowest freezing point?

The one that has the highest ions if all molarity given is the same

Equilibrium expression equation

The product side of the reaction is placed on top, and the reactant side is on the bottom of the expression. The coefficients become the exponents for their respective reactants in the equilibrium constant expression.

Which of these kinetic molecular theory assumptions is true of ideal gases?

The volume of individual gas molecules is negligible

A Lewis acid can be described as a species that

accepts electrons

pKa is the

acid strength

To get the bond order you would do

all all doubles single bond is 1 double bond is 2 then divide by how many single bonds and double bonds there are (in 1s)

What kind of radiation can lab coats protect against?

alpha particles

Because a proton is converting into a neutron, the atomic mass stays the same but the

atomic number decreases by one.

Ionization energy is a result of

atomic size.

The central atom that can most easily accept an electron pair is going to be the

best Lewis acid.

During a titration experiment, the titrant is placed in which of the following?

buret

third row (n=3) of the periodic table the elements are

capable of expanding their valence shell and breaking the octet rule.

Doubling the volume at constant temperature would

decrease the pressure by half.

ionization energy trend

decreases down a group, increases across a period

entropy

described as the measure of disorder, or randomness, in a system.

Distillation separates based on

differences in boiling point

allotrope

different structural forms of the same element

Which process would be used to separate two miscible liquids?

distillation

If the pressure is decreased by half, the volume will .

double

triple bonds are stronger than

double bonds

Ionic bonds are stronger than

intermolecular forces. This liquid would not evaporate as easily.

A spontaneous reaction can produce an

increase in entropy.

As pressure of the gas increases, the solubility of the gas

increases

As temperature of the solution decreases, the solubility of the gas

increases

the strength of the acid increases as the number of oxygens

increases

As pressure of the gas increases, the solubility of the gas

increases.

As temperature of the solution decreases, the solubility of the gas

increases.

the strength of the acid increases as the number of oxygens

increases.

Bond length decreases with

increasing bond order.

Average kinetic energy increases with

increasing temperature.

Enthalpy also changes with

increasing temperatures.

In a covalent substance, melting breaks

intermolecular bonds

n a covalent substance, melting breaks

intermolecular bonds

what occurs if T is decreased for an Endothermic Reaction or T is increased for an Exothermic reaction.

reaction shifts to left

conjugate acid

received proton

An oxidizing agent gets_______. A reducing agent gets _______.

reduced. oxidized.

Diamagnetic means

repelled from magnetic fields. They have all their electrons paired in their orbitals.

a beta particle

represented by 0 a -1

An alpha particle

represented by 4 a 2

Average kinetic energy of gaseous molecules depend

s on absolute temperature. Because the two gases are at the same temperature, their average kinetic energies are the same.

For adding and subtracting, the answer must have the

same number of decimal places as the measurement with the fewest number of decimal places.

Which best describes an isotope?

same number of protons but different number of neutrons

Filtration is an effective technique to

separate a solid from a liquid

crystalline solid

sharp and well defined melting temperature

atom with the smallest atomic size is the one with the

shortest bond length

Double bonds are stronger than

single bonds

If ionization energy is high and electron affinity is high, atomic radii would be

small for both atoms.

Atomic size gets

smaller UP and to the RIGHT of the periodic table.

The partial pressure is tripled, so the

solubility will triple.

Transition metals can form brightly colored compounds because

their d orbitals are unfilled or half filled.

If the partial pressure of the gas is increased,

there will be more interactions between the gas and the solution, increasing solubility.

Pure elemental gases are covalently bonded and are non-polar. As a result,

they have low intermolecular forces acting on the molecules.

A trigonal planar geometry will have

three areas of electron bonding pairs with no non-bonding electron lone pairs.

The electrons flow from the anode

to the cathode

Atomic radius is smallest at the

top right of the periodic table.

beaker

used for stirring, mixing, and heating solutions

Which of the following gases will have the greatest density at STP? A. Cl2 (7%) B. N2O (1%) C. Ar (7%) D. SO3 (84%) E. CO2 (1%)

you do PV=nRT As molecular weight goes up, density goes up.

A gas filled balloon contains triptane gas (C7H16 ; MM = 100 g/mol) and another unknown gas. This balloon develops a pinhole leak. The unknown gas effuses out of the balloon FIVE times as fast as triptane gas. Which of the following could be the unknown gas?

you would do 5= SQ 100/molar mass x then you do 25=100/molarmass then its simple math of 4g/mol H