Nuclear
Which observation proved that radioactive decay is spontaneous and random?
A) Constant activity
B) Linear decay
C) Exponential decay
D) Stepwise decay
C) Exponential decay
For a reaction with ΔH > 0 and ΔS > 0, spontaneity is favoured at:
A) Low temperature
B) High temperature
C) All temperatures
D) No temperature
B) High temperature
Which of the following alkanes has the lowest boiling point?
A) Hexane
B) 2-methylpentane
C) 3-methylpentane
D) 2,2-dimethylbutane
D) 2,2-dimethylbutane
Which solid conducts heat efficiently but does not conduct electricity?
A) Graphite
B) Diamond
C) Sodium chloride
D) Copper
B) Diamond
During electrolysis of aqueous sodium sulfate using inert electrodes, which gas is evolved at the anode?
A) Hydrogen
B) Oxygen
C) Chlorine
D) Nitrogen
B) Oxygen
Who experimentally confirmed the existence of the neutron?
A) Rutherford
B) Bohr
C) Chadwick
D) Curie
C) Chadwick
Which of the following changes would increase the solubility of CaCO₃ in water?
A) Adding Na₂CO₃
B) Decreasing pH
C) Increasing temperature
D) Adding CaCl₂
B) Decreasing pH
Why does benzene undergo substitution rather than addition?
A) Addition increases stability
B) Substitution preserves aromaticity
C) Benzene is non-polar
D) Addition requires UV light
B) Substitution preserves aromaticity
Which of the following molecules is the least polar?
W) Ammonia
X) Nitrogen trifluoride
Y) Nitrogen trichloride
Z) Nitrogen tribromide
X) Nitrogen trifluoride
Increasing electrolyte concentration increases current mainly because:
A) EMF increases
B) Resistance decreases
C) ΔG becomes more negative
D) Electrode potential changes
B) Resistance decreases
Which scientist first discovered radioactivity?
(Antoine Henri) Becquerel
The value of K_c remains constant, but the equilibrium composition changes.
Which change must have occurred?
A) Catalyst added
B) Initial concentrations changed
C) Temperature changed
D) Pressure increased
B) Initial concentrations changed
A compound gives a positive iodoform test but a negative Fehling’s test. What functional group is present?
Methyl ketone
What is the VSEPR predicted molecular geometry of iodine pentafluoride IF5?
Square pyramidal
A galvanic cell has a positive standard EMF but delivers no current. Why?
A) Low electrolyte concentration
B) Reaction quotient equals equilibrium constant
C) High internal resistance
D) Small electrode area
B) Reaction quotient equals equilibrium constant
Which particle explains why beta decay can produce a continuous energy spectrum for emitted electrons and resolved the apparent violation of energy conservation in beta decay?
Neutrino
Two reactions have identical K_c values but different rates.
What differs between them?
Activation energy
Upon addition of one equivalent of methyl Grignard (grin-YARD) to acetic acid, which of the following types of reactions occurs?
A) Oxidation
B) Reduction
C) Substitution
D) Neutralization
D) Neutralization
Which of the following statements about periodic trends is NOT true?
A) Atomic radius generally decreases across a period.
B) Ionization energy generally decreases across a period.
C) Electronegativity generally increases across a period.
D) Metallic character generally decreases across a period.
B) Ionization energy generally decreases across a period.
What industrial process involves the reaction of carbon monoxide with unrefined nickel metal to form nickel tetracarbonyl?
A) Ostwald process
B) Mond process
C) Kroll process
D) Bayer process
B) Mond process
What quantum mechanical phenomenon allows alpha particles to escape the nucleus despite insufficient classical energy?
Quantum tunneling
When gaseous nitrogen dioxide is stored in a closed container, it establishes an equilibrium with its dimer, dinitrogen tetroxide. This exothermic reaction can be represented by the equation
2 NO2 (g) <-> N2O4 (g). Identify all of the following three statements that are true regarding this reaction:
1) As temperature increases, the forward reaction becomes more favorable
2) As temperature increases, the equilibrium constant increases
3) For this reaction at 100 kelvin, Kp > Kc
None
Huckel’s rule is used to predict whether a molecule observes what property, which is the stabilization observed from a fully conjugated, closed-shell pi system?
Aromaticity
Identify which one of the following statements about Boltzmann distribution of energy is false.
A) Degenerate states have the same energy and will be equally populated
B) An exponential increase in population with increasing temperature is predicted
C) More states are significantly populated if energy level spacings are near kT
D) At T = 0, only the lowest energy state is occupied
B) An exponential increase in population with increasing temperature is predicted
Which of the following best explains why chlorine gas is formed instead of oxygen gas during the electrolysis of brine?
A) The oxidation potential of the chloride-chlorine electrode is greater than that of the water-oxygen electrode
B) The oxidation potential of the chloride-chlorine electrode is less than that of the water-oxygen electrode
C) The overpotential of the chloride-chlorine electrode is greater than that of the water-oxygen electrode
D) The overpotential of the chloride-chlorine electrode is less than that of the water-oxygen electrode
D) The overpotential of the chloride-chlorine electrode is less than that of the water-oxygen electrode