Nuclear Chem
Q. Which quantity changes during beta-minus decay?
A) Mass number
B) Atomic number
C) Number of nucleons
D) Binding energy per nucleon
Answer: B Atomic number
Q. Which of the following is NOT true about aqueous solutions:
A) diluting a buffer with water can change the pH of the water
B) metal cations can act as weak acids in water solutions
C) an acid whose Ka = 6 × 10–10 is weaker than an acid whose Ka = 5.8 × 10–4
D) an acid whose pKa is 3.0 is stronger than an acid whose pKa is 7.0
Answer: A
diluting a buffer with water can change the pH of the water
Q. Which of the following is a substance whose molecular and empirical formulas are NOT the same?
A) Benzene
B) Water
C) Ammonia
D) Sulfur dioxide
Answer: A) Benzene
Q. Which of the following is a substance that is very reactive with the oxygen in air and must be stored under water or some other substance to keep it from becoming incendiary?
A) fullerene
B) white phosphorus
C) calcium fluoride
D) calcium oxide
B) White Phosphorus
Q. According to general solubility rules, name all of the following five substances that are NOT soluble in water:
Lithium Iodide; Sodium Chloride; Iron(II) Hydroxide; Sodium nitrate; Barium Sulfate
Answer: Iron(II) Hydroxide; Barium Sulfate
Q. Which pair represents isotopes of the same element?
A) 146X and 147Y
B) 126X and 146X
C) 146X and 157Y
D) 126X and 125Y
B) 126X and 146X
Q. The titration of a weak base, 0.100 molar NaCN, with a strong acid, 0.100 molar HCl, results in a solution at the equivalence point having a pH of:
A) between 7 and 10
B) 7
C) between 4 and 7
D) between 1 and 3
Answer: C) between 4 and 7
Q. An organic compound has the molecular formula C₆H₁₀.
It is unsaturated and can undergo addition reactions with bromine water.
The compound contains one triple bond between carbon atoms.
To which homologous series does this compound belong?
A) Alkane
B) Alkene
C) Alkyne
D) Arene
Answer: C) Alkyne
Q. An aqueous solution in which the concentration of OH⁻ ions is greater than that of H⁺ ions is:
Choose your answer:
A) basic
B) acidic
C) neutral
D) in equilibrium
Answer: A) basic
Q. Which metal acts at the anode in mercury batteries that are commonly found in cameras and watches?
A) mercury
B) mercury(II) oxide
C) zinc
D) lithium
Answer: C) zinc
Q. Which decay mode results in a decrease of mass number by 4?
A) Gamma emission
B) Beta-minus decay
C) Alpha decay
D) Positron emission
Answer: C) Alpha decay
Q. A reaction has K = 10⁻⁸. Which statement is true?
A) Reaction does not occur
B) Reaction is irreversible
C) Forward reaction rate is zero
D) Reactants are strongly favoured
Answer: D) Reactants are strongly favored
Q. Which of the following substances would you expect to be the most miscible with water?
A) Methanol
B) Ethyl acetate
C) 2-Butanal
D) Butyraldehyde
Answer: A) Methanol
Q. In which of the following pairs are both elements classified as semimetals?
A) Tellurium and Tin
B) Selenium and Bromine
C) Scandium and Silicon
D) Arsenic and Germanium
Answer: D) Arsenic and Germanium
Q. What is the oxidation number of chromium in the chromate ion, CrO₄²⁻?
Answer: +6
Q. Which particle discovery forced the revision of Dalton’s claim that atoms are indivisible?
Answer: Electron
Q8. Which of the following is closest to the pKa of an acid whose Ka = 5.0 × 10⁻⁴.
A) 2.3
B) 3.3
C) 4.0
D) 5.0
Answer: B) 3.3
Q. Name the rule governing HX addition to alkenes.
Answer: Markovnikov’s rule
Q. In the periodic table, what are elements 58 through 71 classified as?
Answer: Lanthanides
Q. What element is a corrosive, greenish-yellow gas, is widely used in the manufacturing of polymers such as Teflon, and is the 13th most abundant element in the Earth’s crust?
Answer: Fluorine
Q. Who proposed the plum pudding model of the atom?
A) Ernest Rutherford
B) J. J. Thomson
C) Niels Bohr
D) John Dalton
Answer: B) J.J. Thomson
Q. What is the pH of a solution with a pOH of 6.8 at 25°C?
Answer: 7.2
Q.What is the electrophile in the nitration of benzene?
A) Nitric acid
B) Nitrous acid
C) Nitronium ion (NO₂⁺)
D) Nitrate ion
Answer: C) Nitronium ion (NO₂⁺)
Q. Which of the following correctly explains why concentration cells have a standard cell potential of 0 volts?
A) According to the Nernst equation, the standard cell potential is cancelled out by the concentration-dependent term
B) At standard conditions, all cells have a standard cell potential of 0 volts
C) Standard cell potentials are measured with all species at equal concentrations
D) Concentration cells are used as a standard, so their standard cell potential is arbitrarily set to 0
Answer: C) Standard cell potentials are measured with all species at equal concentrations
Q. Carbon monoxide, or CO, will be adsorbed onto the surface of which of the following metals the MOST strongly?
A) Iron
B) Nickel
C) Cobalt
D) Gold
A) Iron