day1 Flashcards
The distance of the Earth to the most remote normal galaxy is calculate to be
9x10^25 m
distance from earth to nearest known galaxy (Andromeda)
2x10^22 m
distance from Earth to most remote known Quasar
1.4x10^26 m
Distance from Earth to nearest known star (Proxima Centauri)
4x10^16 m
determination of nitrogen based on the conversion of organic nitrogen to ammonia, which is then separated by distillation and determined by titration
kjeldahl method
which of the following pairs will form a buffer solution in the course of a titration?
a. nitric acid, sodium hydroxide
b. sulfuric acid, potassium hydroxide
c. acetic acid, sodium hydroxide
d. hydrochloric acid, potassium hydroxide
c. acetic acid, sodium hydroxide
When a can of soda is opened and CO2 is released to the atmosphere, what is the resultant pH of the soda?
a. decreases
b. increases
c. the same
d. all these
b. increases
define a salt in terms of acid and base
a. a salt is a compound that follows Le Chatelier’s Principle in reactions with other compounds
b. all of these
c. a salt is a compound formed when the nucleus of a hydrogen tom enters a quantity of water
d. a salt is a compound (other than water) produced by the reaction of an acid and a base
d. a salt is a compound (other than water) produced by the reaction of an acid and a base
when benzoic acid dissolves in water, it partially reacts with water and ionizes to form benzoate and hydronium ions. in this reaction, what is the conjugate acid?
a. benzoate ions
b. hydronium ions
c. water
d. benzoic acid
b. hydronium ions
water at room temperature usually has a slightly acidic pH. this is largely attributed to what compound(s)?
a. sulfuric acid
b. dissolved metals
c. carbonic acid
d. nitric acid
c. carbonic acid
are galvanic cells and electrolytic cells the same? why?
a. no, because galvanic cells are electrochemical cells in which chemical cells occur simultaneously; while in electrolytic cells. the chemical reaction is caused by an externally applied potential difference.
b. no, because galvanic cells need a constant supply of electricity while electrolytic cells depend on intermittent source of power
c. yes, because they are both electrochemical cells and their uses are common to each other
d. yes, because galvanic cells and electrolytic cells are both electrochemical cells
a. no, because galvanic cells are electrochemical cells in which chemical cells occur simultaneously; while in electrolytic cells. the chemical reaction is caused by an externally applied potential difference.
what is the significance of colligative property in physical chemistry?
a. it refers to the freezing point depression, boiling point elevation osmotic pressure and lowering of the vapor pressure by a nonvolatile solute.
b. it refers to the temperature, pressure and energy of fusion of volatile solutes in phase equilibrium
c. it refers to the non-existence of pressure among molecules within the solute
d. it refers to the temperature differentials exhibited by non-volatile solutes in reactions
a. it refers to the freezing point depression, boiling point elevation osmotic pressure and lowering of the vapor pressure by a nonvolatile solute.
which of the following statements is true?
a. trouton’s rule fails for highly polar liquids
b. it is impossible to go from vapor phase to liquid phase without condensation
c. for C compounds and P phases, there are a total of CP intensive variables to be specified
d. at high pressures, the latent heat of vaporization is a measure of the strength of the intermolecular forces of the liquid
a. trouton’s rule fails for highly polar liquids
among the following, which compound will produce the lowering of the vapor pressure of a solution?
a. sucrose, c12h22o11
b. aluminum chloride, alcl3
c. table salt, nacl
d. sodium sulfate, na2so4
a. sucrose, c12h22o11
when a solute is introduced to a liquid system the entropy of the said system
a. increases
b. decreases
c. stays the same
d. can’t be determined
a. increases
in a process involving osmosis, at equilibrium, the chemical potential of the pure solvent side should be _____ the chemical potential of the side with solute
a. less than
b. more than
c. equal to
d. can’t be determined
c. equal to
all colligative properties stem from the ____ of the chemical potential of the liquid solvent as a result of the presence of the solute
a. reduction
b. change
c. enlargement
d. a or b or c, depending on the identities of the solute and solvent
a. reduction
for miscible systems, the boiling point of the solution is
a) lower than the boiling point of the liquid with the lower boiling point
b. between the boiling points of the two liquids
c. above the boiling point of the liquid with the higher boiling point
d. cannot be determined
b. between the boiling points of the two liquids
the coexistence curve where the plot of pressure versus temp along which the two phases coexist was shown by clausius clapeyron. what did clausius postulate?
a) the clapeyron equation was simplified by assuming that the vapor obeys the ideal gas law and by neglecting the molat volume of the liquid in comparison with the molar volume of the gas
b. the clausius-clapeyron equation does not apply to this situation
c. the clausius-clapeyron theory is applicable only for vaporization and sublimation condition
d. both scientists apply their postulates to linear and curvilinear representation
a) the clapeyron equation was simplified by assuming that the vapor obeys the ideal gas law and by neglecting the molat volume of the liquid in comparison with the molar volume of the gas
what is the clapeyron equation?
a. any of these
b. it postulates that the colligative properties, freezing point depression, boiling point elevation, osmotic pressure, and vapor pressures are all dependent on the number f particles in the solution and any change thereof is described
c. it postulates that if two components systems consisting of solid and liquid phases are miscible in the liquid state and immiscible in the solid state, only the pure solid systems will separate out on cooling solutions
d. it postulates that if the temperature and pressure are both change in such a way as to keep the chemical potentials of two phases equal to each other, the rates of change are given by the equation.
d. it postulates that if the temperature and pressure are both change in such a way as to keep the chemical potentials of two phases equal to each other, the rates of change are given by the equation.
the clausius-clapeyron equation does NOT apply to
a) S-V equilibrium
b. L-V equilibrium
c. S-L equilibrium
d. None of these
c. S-L equilibrium
the clapeyron equation gives the slope
a) dv/dt
b) dt/dp
c) dt/dv
d) dp/dt
d) dp/dt
it is the property of a fluid that is caused by shearing effect of a fluid layer moving past another layer
a. density
b. viscosity
c. flow.
d. compressibility
b. viscosity
which of the following does not have a zero enthalpy of formation at 298.15 K
a. Li (g)
B. He (g)
c. Hg (l)
d) Br2 (l)
a. Li (g)
choose the process that occurs with a decrease in entropy
a. freezing of water
b. boiling of water
c. dissolving salt in water
d. sublimation of dry ice
a. freezing of water
define entropy
a. entropy is a function of the state of the system and determines whether a physical change or chemical reaction can occur simultaneously in a closed system
b. entropy is the opposite of enthalpy
c. entropy determines the time required for a reaction to proceed and complete
d. all of these
d. all of these
an adiabatic process is one in which the system under investigation is thermally isolated so that there is no exchange of heat with the surroundings. thus, the work done on a closed system in an adiabatic process is ____
a. equal to zero
b. not equal to the exchange of heat with surroundings
c. equal to the increase in internal energy of the system
d. not equal to the increase in internal energy of the system
c. equal to the increase in internal energy of the system
the fugacity of a real gas is equal to:
a. the pressure of an ideal gas which has the same chemical potential as the real gas
b. the pressure of a real gas which has the same chemical potential as the ideal gas
c. the chemical potential of an ideal gas which has the same pressure as the real gas
d. the chemical potential of a real gas which has the same pressure as the ideal gas
a. the pressure of an ideal gas which has the same chemical potential as the real gas
the equilibrium intensive state of a system is described by specifying the temp pressure and
a. mole fractions
b. number of moles
c. volume
d. chemical potential
a. mole fractions
the general statement of the Third Law of Thermodynamics is attributed to
a. Nikolaus Otto
b. Jacobus Clapeyron
c. William Clausius
d. Walther Nernst
d. Walther Nernst
Which of the following statements is/are true?
- the criterion of equilibrium at constant temp and pressure id dG= 0
- for a reversible process, ds=dQ/T
a. 1 only
b. both 1 and 2
c. 2 only
d. none of the above
b. both 1 and 2
heat required to raise the temp of 1 lbm of water by 1F
a. calorie
b. BTU
c. specific heat
d. heat capacity
b. BTU
the amount of heat absorbed when co2 gas reacts with a solid CaO to form solid CaCO3 is measured in a bomb calorimeter. the data obtained give a direct measure of
a. delta U
b. VdeltaP
c. delta H
d. Cp
a. delta U
if the entropy of a system decreases, the entropy of its surroundings
a. must always increase
b. must always decrease
c. may increase or decrease
d. not enough information to answer the question
a. must always increase
increasing the temperature of the cold reservoir ___ the carnot efficiency
a. increases
b. decreases
c. does not change
d. NOTA
b. decreases
An isentropic process is
a. isothermal and adiabatic
b. reversible and isothermal
c. reversible and adiabatic
d. reversible and isochoric
c. reversible and adiabatic
which of the following is not conserved in any process?
a. mass
b. energy
c. momentum
d. entropy
d. entropy
a sample of an ideal gas has an internal energy of U and is then compressed to 1/2 of its original volume while the temperature stays the same. what is the new internal energy of the ideal gas in terms of U?
a. U
b. U/2
c. U/4
d. 2U
a. U
which of the following is a characteristic of an adiabatic process?
a. delta U = 0
b. W = 0
c. Q=0
d. delta V =0
c. Q=0
the internal energy of an ideal gas depends on
a. volume
b. absolute temperature
c. pressure
d. number of moles
c. pressure
this is the pressure exerted by the gas molecules that are in equilibrium with the liquid
a. partial pressure
b. atmospheric pressure
c. total pressure
d. vapor pressure
d. vapor pressure
when gas molecules collide, they experience _ collision
a. perfectly elastic
b. imperfect elastic
c. perfectly inelastic
d. imperfect inelastic
a. perfectly elastic
which of the following is false with KMT?
a. gas molecules move in random motion
b. due to collision of gas molecules with each other, some kinetic energy is lost
c. the temperature of the whole system does not change with time
d. the size of the molecules are negligible
b. due to collision of gas molecules with each other, some kinetic energy is lost