set g Flashcards
A voltaic cell is one in which
a. the standard reduction potentials of the two-half-cell reactions are equal to one another
b. the standard cell voltage is positive
c. the standard cell voltage is negative
d. both a and b are correct
e. both a and c are correct
b. the standard cell is positive
Consider the reaction: A + 2B —> C, and a kinetic study on this reaction yielded:
[A] mol/ L [B] mol/L Rate=mol/L s-1
0.045 0.105 6.82 E-04
0.045 0.210 2.75 E-03
0.135 0.105 2.02 E-03
What order is the reaction with respect to ([A], [B])?
a. 2,2
b. 0,2
c. 1,2
d. 2,1
1,2
Consider 6-Aminopenicillanic acid was used to produce semi-synthetic penicillin by enzymatic hydrolysis of fermentation-derived penicillin G (Benzylpenicillin). The starting concentration of penicillin G is 10% (w/v), and 99% conversion is required. Enzymatic conversion of penicillin G can be considered a first-order reaction. The downtime between batch reactions is expected to be 20 h. For the batch and CSTR reactors, the reaction rate constant is 0.8 E-04 /s; in the PFTR, the packing density of enzyme beads can be up to four times greater than in the other reactors. Determine the batch reactor volume required to treat 400 tons of penicillin G per year.
a. 33 m3
b. 157 m3
c. 16.5 m3
d. 3.66 m3
e. 1.83 m3
potential answer: 16.5 m3
Which of the following statement is incorrect about thermodynamic standard states?
a. For a pure substance in the liquid or solid phase, the standard state is the pure liquid or solid.
b. For a gas mixture, the standard state is the gas at a pressure of one bar.
c. In a gas mixture, its partial pressure must be one atmosphere.
d. For a substance in solution, the standard state refers to one-molar concentration.
e. The standard temperature of most pure substances is at 298 K.
For a gas mixture, the standard state is the gas at a pressure of one bar.
A buffer solution may result if K3PO4 is mixed with
a. K2HPO4
b. HCl
c. NaOH
d. Either HCl or K2PO4
e. Either K2PO4 or NaOH
Either HCl or K2PO4
Beta emission can best be described a involving
a. Transformation of a neutron into a electron, and a proton that is ejected from the nucleus.
b. Transformation of a neutron in a proton, and an electron that is ejected from the nucleus.
c. Emission from an unstable nucleus of a fragment containing two protons and two neutrons.
d. Annihilation of a beta particle by a positron.
e. Capture of an electron by the nucleus and transformation of a proton into a neutron.
b. Transformation of a neutron in a proton, and an electron that is ejected from the nucleus.
For which of the following molecules will the electron-pair geometry be the same as the molecular geometry?
a. ICl6^+
b. NO2^-
c. ClF3
d. SeH2
e. NF3
ICl6^+
Which of the following does not transfer work to or from a system?
a. A membrane that bursts
b. An electrical resistance heater
c. The expanding membrane of a balloon
d. A moving piston
A membrane that bursts
A solution containing an unknown cation was added to three solutions and the following observations were recorded:
Solution Observation
NaI No precipitate
Na2SO3 Precipitate
NaOH No precipitate
The unknown cation is
a. Sr2+
b. K+
c. Pb2+
d. Ca2+
e. Ag+
Ca2+
Determine the formula for an alkyne, alkene, and alkane containing 3 carbons.
a. C3H3 C3H6 C3H4
b. C3H4 C3H6 C3H8
c. C3H6 C3H8 C3H10
d. C3H6 C3H10 C3H8
e. C3H4 C3H8 C3H6
b. C3H4 C3H6 C3H8
[alkyne CnH(2n-2); alkene CnHn; alkane CnH(2n+2)]
The heat capacity of a substance can be measured under either constant-volume or constant-pressure conditions. Which of the following sets of relationships between Cv (heat capacity under constant volume conditions) and Cp (heat capacity under constant-pressure conditions) are always true?
a. Cp (gas) > Cv (gas); Cp (solid) ~ Cv (solid); Cp (gas)»_space; Cp (solid)
b. Cv (gas) ~ Cv (solid) and Cp (liquid) ~ Cv (liquid)
c. Cv (gas) > Cv (liquid) > Cv (solid) and Cv > Cp in all phases
d. Cp approaches a value of 0 as the sample temperature approaches 0 K but increases without bound as the sample temperature is increased.
a. Cp (gas) > Cv (gas); Cp (solid) ~ Cv (solid); Cp (gas)»_space; Cp (solid)
A key concept in analyzing the filling of an evacuated tank is:
a. The temperature in the tank remains constant
b. The internal energy in the tank remains constant
c. The mass flow rate into the tank remains constant
d. The enthalpy across a valve remains constant
d. The enthalpy across a valve remains constant
Clean air
a. contains mostly oxygen, some nitrogen and nothing else.
b. contains mostly nitrogen, some oxygen, and a very small amount of several other gases.
c. has all of its nitrogen removed.
d. is pure oxygen
e. contains mostly nitrogen, some oxygen and nothing else.
contains mostly nitrogen, some oxygen, and a very small amount of several other gases.
Mesh number of screens indicate the number of openings per
a. linear inch
b. square inch
c. screen radius
d. screen diameter
a. linear inch
Why is the turbulence of particle flow achieved at a lower Reynolds Number (> 500) compared to normal fluid only in a pipe (> 2100)?
a. It is because of the friction created by the particle on the fluid.
b. It is because of the viscosity of the fluid and it helps increase the particle velocity.
c. I don’t know the reason.
d. It is because the particle contributes in the formation of eddies at the rear of the particle.
d. It is because the particle contributes in the formation of eddies at the rear of the particle.
