Chemistry Exam

Which equation represents a neutralization reaction? A) 6HClO → 4HCl + 2HClO₃ B) CH₄ + 2O₂ → CO₂ + 2H₂O C) Ca(OH)₂ + H₂SO₄ → CaSO₄ + 2H₂O D) Ba(OH)₂ + Cu(NO₃)₂ → Ba(NO₃)₂ + Cu(OH)₂

C

Which equation represents fermentation? A) C₂H₄ + H₂O → CH₃CH₂OH B) C₂H₄ + HCl → CH₃CH₂Cl C) C₆H₁₂O₆ → 2CH₃CH₂OH + CO₂ D) 2CH₃CHO → + C₃H₅CHO + H₂O

C

Which of the following represents a mixture in a container? A) H₂O H₂O B) OH- OH- C) OH- H H D) O₂ O₂ O₂ O₂

C

Which phase change results in an increase in entropy? A) I₂(g) → I₂(s) B) CH₄(g) → CH₄(l) C) Br₂(l) → Br₂(g) D) H₂O(l) → H₂O(s)

C

Consider the following equation: Pb-208 + Zn-70 → 277Cn + 1 Neutron Which type of reaction is represented by this equation? A) Neutralization B) Polymerization C) Substitution D) Transmutation

D

Given the system: PCl₅(g) ⇌ PCl₃(g) + Cl₂(g) Which statement describes this system? A) The concentration of PCl₅(g) is increasing B) The concentration of PCl₅(g) is decreasing C) The concentration of PCl₅(g) and PCl₃(g) are equal D) The concentration of PCl₅(g) and PCl₃(g) are constant

D

In the ground state, an atom of which element has seven valence electrons? A) Sodium B) Phosphorous C) Nitrogen D) Fluorine

D

In which type of nuclear reaction do two light nuclei combine to produce heavier nuclei? A) Positron emission B) Gamma emission C) Fission D) Fusion

D

What is the colour of bromocresol green indicator in a solution with a pH of 2.0? A) Blue B) Green C) Red D) Yellow

D

Which compound is an isomer of C₂H₅OC₂H₅? A) CH₃COOH B) C₂H₅COOCH₃ C) C₂H₇COCH₃ D) C₄H₉OH

D

Which electron configuration could represent the electrons in a sodium atom in an excited state? A) 2-8 B) 2-8-1 C) 2-7-1 D) 2-7-2

D

Which formula represents an asymmetrical molecule? A) CH₄ B) CO₂ C) N₂ D) NH₃

D

Which statement describes the energy and bonding changes as two atoms of fluorine become a molecule of fluorine? A) Energy is absorbed as a bond is broken. B) Energy is absorbed as a bond is formed. C) Energy is released as a bond is broken. D) Energy is released as a bond is formed.

D

As the elements in period 2 of the Periodic Table are considered in order from left to right, which property generally decreases? A) Atomic radius B) Electronegativity C) Ionization energy D) Nuclear charge

A

Distillation is a process used to separate a mixture of liquids based on different A) Boiling points B) Densities C) Freezing point D) Solubilities

A

Given the equation: C₂H₄ + F₂ → C₂H₄F₂ Which type of reaction is represented by the equation? A) Addition B) Fermentation C) Polymerization D) Substitution

A

Given the structure: CH₃CH₂CH₂COOCH₃ What is the name of this compound? A) Methyl butanoate B) Methyl butyl ether C) Pentanone D) Pentanoic acid

A

In a titration, 10.0 mL of 0.0750 M HCl(aq) is exactly neutralized by 30.0 mL of KOH(aq) of unknown concentration. What is the concentration of the KOH(aq) solution? A) 0.0250 M B) 0.0750 M C) 0.225 M D) 0.333 M

A

The diagram below represents the bright-line spectra of four elements and a bright-line spectrum produced by an unidentified element. Element L | | | | | Element M | | | || | Element X || | | | | Element Z | | Element ? | | | | | What is the unidentified element? A) L B) M C) X D) Z

A

Which Lewis electron-dot diagram represents the bonding in potassium iodine? A) K+[:I:]- B) [:K:]-I++ C) K:I: D) :K:I

A

Which compounds are classified as electrolytes? A) KNO₃ and H₂SO₄ B) KNO₃ and CH₃OH C) CH₃OCH₃ and H₂SO₄ D) CH₃OCH₃ and CH₃OH

A

Which radioisotope is used to determine the age of once-living organisms? A) Carbon-14 B) Cobalt-60 C) Iodine-131 D) Uranium-238

A

Which statement describes the reactions in an electrochemical cell? A) Oxidation occurs at the anode, and reduction occurs at the cathode. B) Oxidation occurs at the cathode, and reduction occurs at the anode. C) Oxidation and reduction both occur at the cathode. D) Oxidation and reduction both occur at the anode.

A

A solid sample of copper is an excellent conductor of electric current. Which type of chemical bonds are in the sample? A) Ionic bonds B) Metallic bonds C) Nonpolar covalent bonds D) Polar covalent bonds

B

An orbital is a region in an atom where there is a high probability of finding A) an alpha particle B) an electron C) a neutron D) a positron

B

Consider the following system: H₂(g) + I₂(g) + ENERGY ⇌ 2HI(g) When the concentration of H₂(g) is increased by adding more hydrogen gas to the container at a constant temperature, the equilibrium shifts A) to the right, and the concentration of HI(g) decreases B) to the right, and the concentration of HI(g) increases C) to the left, and the concentration of HI(g) decreases D) to the left, and the concentration of HI(g) increases

B

Two atoms that are different isotopes of the same element have A) The same number of protons and the same number of neutrons B) The same number of protons but a different number of neutrons C) A different number of protons and the same number of neutrons D) A different number of protons but a different number of neutrons

B

Using an endothermic potential energy diagram: What numbered interval represents the heat of reaction? A) 1 B) 2 C) 3 D) 4

B

Which element has chemical properties that are most similar to potassium A) Calcium B) Cesium C) Nitrogen D) Sulfur

B

Which element is malleable at STP? A) Chlorine B) Copper C) Helium D) Sulfur

B

Which equation represents a single-replacement reaction? A) 2Al(s) + 3Cl₂(g) → 2AlCl₃(s) B) 2Al(s) + 6HCl(aq) → 2AlCl₃(s) + 3H₂(g) C) 2AlCl₃(s) → 2Al(s) + 2Cl₂(g) D) AlCl₃(s) + 3KOH(aq) → Al(OH)₃(s) + 3KCl(aq)

B

Which half-reaction equation represents reduction? A) Cu → Cu²+ + 2e- B) Cu²+ + 2e- → Cu C) Ag + e → Ag+ D) Ag+ → Ag + e

B

Which substance is an Arrhenius acid? A) H₂ B) HCl C) KCl D) NH₃

B

Which two characteristics describe a gas? A) No definite shape, but a definite volume B) No definite shape and no definite volume C) A definite shape and a definite volume D) A definite shape, but no definite volume

B

Dating once-living organisms is an example of beneficial use of A) Redox reactions B) Organic isomers C) Radioactive isotopes D) Neutralization reactions

C

Given the balanced equation: 2C₄H₁₀ + 13O₂ → 8CO₂ How many moles of carbon dioxide are produced when 5.0 moles of butane reacts completely? A) 5.0 mol B) 10. mol C) 20. mol D) 40. mol

C

Given the equation: Cd + NiO₂ + H₂O → Cd(OH)₂ + Ni(OH)₂ Which half-reaction equation represents in the reaction? A) Ni⁴+ + 2e- → Ni²+ B) Ni⁴+ → Ni²+ + 2e- C) Cd → Cd²+ + 2e- D) Cd + 2e- → Cd²+

C

The following constant half-life: 1,000 radioactive atoms/0 hours → 500 radioactive atoms/0 hours Based on the graph, the half-life of this radioactive isotope is A) 6 Hours B) 9 Hours C) 3 Hours D) 12 Hours

C

What is the amount of heat released when 1.00 gram of liquid water at 0°C when it changes to 1.00 gram of ice at 0°C? A) 4.18 J B) 273 J C) 334 J D) 2260 J

C

What is the per cent composition by mass of nitrogen in the compound N₂H₄ (gram-formula mass = 32g/mol)? A) 13% B) 44% C) 88% D) 93%

C