Atomic Structure & Periodicity
Which of the following elements has the largest atomic radius?
A) Na
B) Mg
C) Al
D) Si
A) Na
In which of the following compounds is the bond between atoms predominantly ionic?
A) HCl
B) NaCl
C) CO2
D) H2O
B) NaCl
Which of the following reactions is most likely to be spontaneous at all temperatures?
A) ΔH>0ΔH>0 and ΔS<0ΔS<0
B) ΔH<0ΔH<0 and ΔS>0ΔS>0
C) ΔH>0ΔH>0 and ΔS>0ΔS>0
D) ΔH<0ΔH<0 and ΔS<0ΔS<0
B) ΔH<0ΔH<0 and ΔS>0ΔS>0
What is the product of the reaction between an acid and a base?
A) Salt and water
B) Carbon dioxide and water
C) Salt and carbon dioxide
D) Water and hydrogen gas
A) Salt and water
Which of the following is true for a buffer solution?
A) It resists changes in pH when small amounts of acid or base are added.
B) It always has a pH of 7.
C) It can only contain a weak acid and its conjugate base.
D) It can only be used for strong acids and bases.
A) It resists changes in pH when small amounts of acid or base are added.
Which of the following is true about the ionization energy of elements in the periodic table?
A) Ionization energy decreases from left to right across a period.
B) Ionization energy increases from left to right across a period.
C) Ionization energy decreases as you move down a group.
D) Ionization energy is unaffected by atomic size.
B) Ionization energy increases from left to right across a period.
Which of the following elements typically forms covalent bonds with hydrogen?
A) Lithium
B) Oxygen
C) Sodium
D) Potassium
B) Oxygen
Which of the following factors does not affect the rate of a chemical reaction?
A) Temperature
B) Concentration of reactants
C) Pressure (for gases)
D) The color of the reactants
D) The color of the reactants
Which of the following is an example of a double displacement reaction?
A) NaCl + AgNO3 → NaNO3 + AgCl
B) H2 + O2 → H2O
C) CaO + CO2 → CaCO3
D) Na + Cl2 → NaCl
A) NaCl + AgNO3 → NaNO3 + AgCl
Which of the following is a strong base?
A) NaOH
B) NH3
C) CH3COOH
D) H2SO4
A) NaOH
Which of the following elements has the highest electronegativity?
A) Na
B) F
C) Cl
D) O
B) F
Which of the following molecules is polar?
A) CO2
B) CH4
C) H2O
D) BF3
C) H2O
Which of the following reactions is exothermic?
A) Melting of ice
B) Combustion of methane
C) Sublimation of dry ice
D) Vaporization of water
B) Combustion of methane
Which of the following statements about catalysts is correct?
A) Catalysts are consumed in a reaction.
B) Catalysts increase the activation energy of a reaction.
C) Catalysts speed up reactions by providing an alternative reaction pathway.
D) Catalysts decrease the rate of reaction.
C) Catalysts speed up reactions by providing an alternative reaction pathway.
What is the pH of a 0.0010 M HCl solution?
A) 4
B) 3
C) 2
D) 1
C) 2
Which of the following best explains the trend in atomic radius as you move across a period in the periodic table?
A) The number of electron shells increases, causing the atomic radius to increase.
B) Electrons are added to the same energy level, and the increased nuclear charge pulls electrons closer.
C) The nuclear charge decreases, making the atomic radius smaller.
D) The shielding effect increases, resulting in a larger atomic radius.
B) Electrons are added to the same energy level, and the increased nuclear charge pulls electrons closer.
Which of the following statements about ionic bonds is correct?
A) Ionic bonds are formed between two nonmetals.
B) Ionic bonds involve the sharing of electrons.
C) Ionic compounds tend to have high melting and boiling points.
D) Ionic compounds are poor conductors of electricity in solid form.
C) Ionic compounds tend to have high melting and boiling points.
Which of the following is true according to the second law of thermodynamics?
A) The total energy in a system is constant.
B) Entropy tends to increase in an isolated system.
C) All spontaneous processes are endothermic.
D) Energy is always conserved in a chemical reaction.
B) Entropy tends to increase in an isolated system.
Which of the following reactions is an example of a redox reaction?
A) NaOH + HCl → NaCl + H2O
B) Zn + CuSO4 → ZnSO4 + Cu
C) H2 + Cl2 → 2HCl
D) N2 + 3H2 → 2NH3
B) Zn + CuSO4 → ZnSO4 + Cu
Which of the following compounds is a Lewis acid?
A) NH3
B) BF3
C) H2O
D) CH4
B) BF3
What is the electronic configuration of a neutral magnesium (Mg) atom?
A) [Ne]3s^2
B) [He]2s^2
C) [Ar]3p^2
D) [Ne]3p^1
A) [Ne]3s^2
Which of the following molecules has a linear molecular geometry?
A) CO2
B) H2O
C) NH3
D) CH4
A) CO2
What is the activation energy in a chemical reaction?
A) The energy required to break the bonds in the reactants.
B) The difference between the energy of the reactants and products.
C) The minimum energy required for reactants to form products.
D) The energy released during the formation of bonds in products.
C) The minimum energy required for reactants to form products.
What is the oxidation number of sulfur in SO2SO2?
A) -2
B) +2
C) +4
D) +6
C) +4
What is the conjugate acid of NH3NH3?
A) NH2−NH2−
B) NH4+NH4+
C) H2OH2O
D) H+H+
B) NH4+NH4+