Oct 2021 Flashcards
Determine whether the following statements are TRUE or FALSE.
a. For all adiabatic processes, the entropy change of the system must be zero
b. For one component system, it is possible for two phases in equilibrium to have different chemical potentials.
c. The change in Gibb’s free energy can be negative for a cyclic process.
d. A condition for equilibrium is that(∆A) T, F =0
a. T, T, T, T
b. F, T, F, T
c. T, F, T, F
d. F, F, F, F
NA
Determine whether the changes in entropy(∆S) and enthalpy (∆H) are POSITIVE, NEGATIVE or near ZERO.
a.) Ethyl alcohol evaporating from glass container b.) A diatomic molecule dissociates into atoms c.) Charcoal is burned to form CO2 and water
a. a.) ∆H>0, ∆S>0; b.) ∆H>0, ∆S>0; c.) ∆H>0, ∆S>0
b. a.) ∆H<0, ∆S<0; b.) ∆H>0, ∆S<0; c.) ∆H>0, ∆S<0
c. a.) ∆H>0, ∆S<0; b.) ∆H<0, ∆S>0; c.) ∆H>0, ∆S>0
d. a.) ∆H<0, ∆S>0; b.) ∆H<0, ∆S<0; c.) ∆H<0, ∆S<0
(chatgpt answer)
a.) ∆H>0, ∆S>0; b.) ∆H>0, ∆S>0; c.) ∆H>0, ∆S>0
Determine whether TRUE or FALSE about the constitutional isomer.
A.) They have the same molecular formula
B.) They have the same molecular weight
C.) They have the same connectivity to their atoms
D.) They have the same physical properties
a. T;F;F;F b. T;T;F;F c. F;T;T;T d. F;F;T;T
T;T;F;F
Determine which of the following occurences telss us what happens when Le Chateier’s principle is applied whether these are TRUE or FALSE
A.) The addition of a component causes the equilibrium to shift to the opposite side
B.) The removal of the component causes the equilibrium to the side from which the component is removed
C.) Increasing the temperature drives an exothermic equilibrium to the side of the reactants, an endothermic equilibrium to the side of the product.
D.) The addition of a catalyst has NO effect on the position of the equilibrium
a. T;F;T;F b. T;T;T;T
c. F;T;F;T d. F;F;F;F
T;T;T;T
Explain the difference in structure between a saturated hydrocarbon from an unsaturated hydrocarbon.
A. Any of these
B. A saturated hydrocarbon contains only carbon-carbon single bonds, while an unsaturated hydrocarbon contains one or more carbon-carbon double or triple bonds.
C. A saturated hydrocarbon is used mainly in cheaper forms of gasolines for vehicle use, while unsaturated hydrocarbons compose most of the gasoline formulae used by current gasoline manufacturers.
D. A saturated hydrocarbon can no longer accept any hydrocarbon or inorganic element and compound, while an unsaturated hydrocarbon is more flexible in reaction mechanisms.
A saturated hydrocarbon contains only carbon-carbon single bonds, while an unsaturated hydrocarbon contains one or more carbon-carbon double or triple bonds.
What is the Nujol Mull in organic chemical reactions?
A. It is a mass spectrum technique and is obtained by grinding up solid which is mixed with mineral oil to form a suspension for IR spectroscopy.
B. It is the name of a type of paraffin oil from India and most often used in gas chromatography to enhance the mass transfer properties of compounds.
C. It. is a process applied for inorganic compounds to determine the effervescence of the compound under study.
D. It is suspension in mineral oil which is placed in between HgCl, AgI and, KCl or stainless steel plates to obtain a good spectrum.
It is a mass spectrum technique and is obtained by grinding up solid which is mixed with mineral oil to form a suspension for IR spectroscopy.
When travelling at NLEx at 80 mph, a stopped car in front causes you to suddenly skid to a stop. What happened to the kinetic energy of the moving car?
A. Some of it were converted to internal energy and some transferred to the road and surroundings.
B. It was transferred to the internal energy of the road.
C. All of it transferred to the road and surroundings.
D. All of it are still in the car.
(chatgpt answer)
Some of it were converted to internal energy and some transferred to the road and surroundings.
What is the theory in two or three dimensional collision to be applied when playing billiards and in order to sink the target ball in the corner pocket?
A. The center of the mass theory where the center of the mass of the system moves as all the mass in the system were concentrated at that point., and one of them is initially at rest, and they were in perpendicular direction of the collision.
B. Proton - proton elastic collision.
C. The component of momentum an isolated system in each of the directions (X, Y, Z) are conserved independently.
D. Where two equal masses undergo a glancing elastic collision
Where two equal masses undergo a glancing elastic collision (partially sure)
To which subatomic particle does each statement refer to a) has a positive charge; b) is found outside of the nucleus; c) has the smallest mass; d) has a negative charge?
A. proton, electron, electron, and electron
B. proton, electron, proton, electron
C. electron, electron, proton, proton
D. D. electron, proton, electron, proton
proton, electron, electron, and electron
Give the technical names of: Sc 3+; Ti 2+; and Sr 2+
A. Transition metal ions
B. Scandium 3 plus ionon; Titanium 2 plus ion ; Strontium 2 plus
c. Scandium (III) ion; Titanium. (II) ion; Strontium ion
D. Scandium 44/31 ion; Titanium 47/22 ion; Strontium 87/38 ion
(chatgpt answer)
Scandium (III) ion; Titanium. (II) ion; Strontium ion
The coexistence curve where the plot of pressure versus temperature 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 molar volume of the liquid VI In comparison with the molar volume of the gas Vg
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 molar volume of the liquid VI In comparison with the molar volume of the gas Vg
Define the relationship between the number of electrons in the valence shell and the number of covalent bonds it forms; a) carbon, b) nitrogen, c) oxygen, and d) hydrogen:
A. C = 4 electrons; 4 bonds
N = 5 electrons; 3 bonds
O = 6 electrons; 2 bonds
H = 2 electrons; 2 bonds
B. C = 5 electrons; 2 bonds
N = 6 electrons; 4 bonds
O = 3 electrons; 1 bonds
H = 2 electrons; 3 bonds
C. C = 6 electrons; 13 bonds
N = 4 electrons; 2 bonds
O = 2 electrons; 1 bonds
H = 2 electrons; 1 bonds
D. C = 2 electrons; 4 bonds
N = 3 electrons; 3 bonds
O = 2 electrons; 2 bonds
H = 4 electrons; 3 bonds
C = 4 electrons; 4 bonds
N = 5 electrons; 3 bonds
O = 6 electrons; 2 bonds
H = 2 electrons; 2 bonds
In a standard chemical reaction, rate is governed by the relationship rate = p.z.e - (Ea/RT) ,
where p and z refer to the probability that reacting molecules make a favorable encounter. To increase the probability of reaction, enzymes are employed. Based on the above equation, if Ea is the activation energy, which is more favorable and why? A lower or higher Ea?
A. Lower Ea so that more molecules possess sufficient energy to react.
B. Higher Ea so that a better nucleophile and electrophile are catalyzed.
C. Lower Ea so that a proton can be donated or stolen for the reactants leading to better catalysis.
D. Higher Ea so the bonds of the reactants will be strained and provide more power transition state condition.
Lower Ea so that more molecules possess sufficient energy to react.
When a can of soda is opened and CO, is released to the atmosphere, what is the resultant pH of the soda?
A. decreases
B. increases
C. the same
D. all these
(chatgpt answer)
increases
What are sigmatropic rearrangements in organic reactions?
A. They are similar to the. (3, 2) Cope rearrangement where the beta ring of a steroid undergoes photon activated retro electrocyclization.
B. They are thermal reactions which do not allow the formation of six membered benzene ring with a cis-or trans -alkene, such as in the formation of vitamin D3.
C. They are different from electrolytic reactions wherein a movement of a sigma bond with a simultaneous rearrangement of the pi-system does not occur.
D. They are not the same to the (3, 3) Cope arrangement and the beta ring does not undergo photon activated retro electrocyclization.
(chatgpt answer)
They are different from electrolytic reactions wherein a movement of a sigma bond with a simultaneous rearrangement of the pi-system does not occur.
Choose the process/es that occur/s with a decrease in entropy.
A. freezing of water
B. boiling of water
c. dissolving salt in water
D. sublimation of dry ice
freezing of water
Determine which of the following substances will float or sink in water: balsa wood, ethylene, glycol; table salt, ethanol.
A. float, sink, sink, float
B. float, float, float, float
C. sink, flat, sink, float
D. sink, sink, sink, sink
float, sink, sink, float
In the study of fats and lipids, determine which of the two triglycerides has a higher melting point, Substance A - containing only lauric acid and glycerol, or Substance B - containing only stearic acid and glycerol?
A. B
B. A
C. both have the same melting point
D. none of these
Substance B
What type of polymer is used for bulletproof vests?
A. Linear polyethylene fiber
C. Polycarbonate fiber
B. Polyacrylonitrate fiber
D. Polymethacryclate fiber
Linear polyethylene fiber
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
equal to the Increase in internal energy of the system
Determine the BEST combination of plant and location to best conserve the environment, given the following data:
Kd = deoxygenation rate constant
Kr = reaeration rate constant.
Tc = Travel time of wastewater discharge
D = oxygen deficit
DO = dissolved oxygen actual concentration
Factor Sugar Plant (A)
Pasig River (PR) Marikina River (MR)
Kd 0.15 0.15
Kr 0.17 0.25
Tc 5.18 4.10
D 7.98 6.62
DO 0.40 1.76
Factor Ethanol Plant (B)
Pasig River (PR) Marikina, River (B)
Kd 0.11 0.10
Kr 0.17 0.25
Tc 5.86 1.47
D 6.51 3.32
DO 1.87 3.06
A. Plant (B) in Marikina River
B. Plant (B) in Pasig River
C. Plant (A) in Marikina River
D. Plant (A) in Pasig River
Plant (B) in Marikina River
Determine whether the changes in entropy and enthalpy are POSITIVE, NEGATIVE Of ZERO;
ethyl alcohol evaporating from a glass container
a diatomic molecule dissociates into, atoms
charcoal is burned to form CO2 and water
A. ΔH > 0, ΔS < 0; ΔH < 0, ΔS > 0; ΔH > 0, ΔS > 0
B. ΔH > 0, ΔS < 0; ΔH > 0, ΔS > 0; ΔH < 0, ΔS > 0
C. ΔH < 0, ΔS < 0; ΔH < 0, ΔS > 0; ΔH < 0, ΔS > 0
D. ΔH < 0, ΔS < 0; ΔH > 0, ΔS > 0; ΔH > 0, ΔS < 0
ΔH > 0, ΔS < 0; ΔH > 0, ΔS > 0; ΔH < 0, ΔS > 0
Make an educated guess whether “Gibbs” free energy ΔG for the following reaction is more negative or less negative than the enthalpy change ΔH:
C2H2 (l) + O2 (g) → H2O (l) + CO2
A. Since ΔS is negative, ΔG is less negative than ΔH.
B. Since ΔS is positive, ΔG is more negative. than ΔH.
c. Since ΔS is positive, ΔG is less negative than AH.
D. Since ΔS is negative, ΔG is more negative than ΔH.
Since ΔS is negative, ΔG is less negative than ΔH.
Determine whether a closed cylinder piston will rise, fall or remain in the same position, if a mixture of one gram butane gas and oxygen were ignited with no heat escaping to the surrounding (Balance the resultant equation and determine the enthalpy change in the reaction to derive the answer).
C4H10 (g) + O2 (g) → CO2 (g) + H2O (l)
A. rise
B. the same
c. fall
D. the cylinder will expand and break
rise
Which has a higher absolute entropy at a temperature of 25 deg, cyclopropane or propylene? Why?
A. Both have the same absolute entropy at normal temperature.
B. Propylene due to the free rotation around the carbon-carbon single bond.
C. Cyclopropane due to the free rotation around the carbon-carbon double bond
D. None of these
Propylene due to the free rotation around the carbon-carbon single bond.
Adrenaline is produced in the body through a biochemical nucleophilic substitution reaction where:
A. the leaving groups are larger and more complex than the halogen atoms frequently in nucleophilic substitution reactions
B. according to Markovnikov’s rule, the biosynthesis of epinephrine adds a hydrogen atom to the
double bonded carbon atom.
C. the nucleophilic nitrogen atom of norepinendrine from a covalent bond with the CH3 of S adenosylmethionine
D. the reactant nucleophile atom replaces the leaving group in the nucleophilic substitution reaction
(chatgpt answer)
the nucleophilic nitrogen atom of norepinendrine from a covalent bond with the CH3 of S adenosylmethionine
Fatty acid such as laurie acid and palmitic acid and oleic acid are long unbranched carboxylic acids consisting of 12 to 20 carbon atoms. Which type of fatty acid should people avoid ingesting, saturated or unsaturated and why?
A. Saturated, because the risk of cardiovascular disease is increased.
B. Fatty acids are safe to ingest.
C. Unsaturated, because the risk of cardiovascular disease is increased.
D. Both fatty acids, because the risk of cardiovascular disease is increased.
Saturated, because the risk of cardiovascular disease is increased.
Of the following pairs of physical systems, determine the one with greater chemical potential.
a) (1A); one mole of H2O (1) at 100.1 degC; or (1B); one mole of H2O (g) at 102 degC.
b) (2A); ten grams of Fe at 2 degC or (2B) ten grams of Fe at 36 degC.
c) (3A); 25 liters of air at 1 atm pressure or (3B) the same amount of air compressed isothermally to 100 atm.
A. 1A, 2B, 3A
B. 1B, 2B, 3B
C. 1A, 2A, 3A
D. 1B, 2A, 3B
1B, 2B, 3B
