Chemistry Practice Test #8

C. 6 hours

A chemical compound X decomposes with a half-life of 3 hours. Suppose there are 20 grams of X in a container, how long will it take for only 5 grams of X to be left in the container? A. 1.5 hours B. 3 hours C. 6 hours D. 9 hours E. 27 hours

C. CS2 ; c = 0.992 J/(K kg)

A container that contains several different compounds is heated to 150°C. Which of the following compounds would increase its temperature the quickest? A. H2O ; c = 4.18 J/(K kg) B. CH3COOH ; c = 2.043 J/(K kg) C. CS2 ; c = 0.992 J/(K kg) D. HNO3 ; c = 1.72 J/(K kg) E. C3H6O ; c = 2.15 J/(K kg)

D. Thorium

A uranium atom undergoes alpha decay. What would be a possible product? A. Radium B. Curium C. Protactinium D. Thorium E. Plutonium

E. O2

All of the following are diamagnetic in their ground state form EXCEPT one. Which one is the EXCEPTION? A. F- B. F2 C. H- D. Li+ E. O2

B. High temperature

An endothermic reaction is shown below. Under what conditions is the reaction spontaneous? CH4(g) + NH3(g) → HCN(g) + 3 H2(g) ΔH° = +251 kJ/mol A. Low temperature B. High temperature C. High pressure D. Low pressure

C. 13 mL, 15 mL

Below is a picture of two graduated cylinders containing water. Which of the following correctly displays how to record the two volumes below? A. 13 mL, 13 mL B. 13 mL, 14 mL C. 13 mL, 15 mL D. 14 mL, 14 mL E. 14 mL, 15 mL

B. 2

Consider a container that holds He and CH4 gas. If there is a hole in this container, how many times faster will the faster gas effuse? A. 1.5 B. 2 C. 3 D. 4 E. 5

A. Filtration

Each of the following laboratory techniques can be used to separate an organic mixture EXCEPT one. Which one is the EXCEPTION? A. Filtration B. Gas chromatography C. Distillation D. Centrifuge E. Thin layer chromatography

D. KNO3

Each of the following nitrate salts will form a precipitate when combined in solution with NaF EXCEPT one. Which one is the EXCEPTION? A. Pb(NO3)2 B. Hg(NO3)2 C. AgNO3 D. KNO3

B. 2

In the combustion reaction of methane, how many moles of O2 are required to produce 2 moles of H2O? A. 1 B. 2 C. 3 D. 4 E. 5

C. Moles of solute ÷ kilograms of solvent

The definition of molality is best defined by _________________. A. Grams of solute ÷ kilograms of solvent B. Grams of solute ÷ liters of solution C. Moles of solute ÷ kilograms of solvent D. Moles of solute ÷ liters of solution E. Moles of solute ÷ moles of solvent

B. NH4+(aq), HCN (aq)

What are the Bronsted-Lowry acids on both sides of the chemical equilibrium below? NH4+(aq) + CN-(aq) ⇄ NH3(aq) + HCN(aq) A. NH4+(aq), CN- (aq) B. NH4+(aq), HCN (aq) C. NH3 (aq), HCN (aq) D. NH3 (aq), CN- (aq) E. NH4+(aq), NH3 (aq)

E. There are less gas molecules

What happens if the temperature is lowered for a liquid in a sealed container? A. The pressure would increase B. The total number of all molecules inside the container decreases C. The vapor pressure of the liquid increases D. The boiling point of the liquid increases E. There are less gas molecules

D. 3

What is the correct number of unpaired electrons in cobalt? A. 0 B. 1 C. 2 D. 3 E. 4

C. Fe2O3

What is the empirical formula of a molecular structure that contains Fe (III) and O? A. FeO B. Fe3O C. Fe2O3 D. Fe2O2 E. Fe4O6

C. NO2

What is the empirical formula of a molecule with 7g of nitrogen and 16g of oxygen? A. NO B. N2O C. NO2 D. NO3 E. N2O2

C. 9

What is the number of valence electrons in a Cu2+ ion? A. 2 B. 7 C. 9 D. 10 E. 11

D. 10

What is the pOH of an HCl solution with a [H+] concentration of 0.0001? A. 4 B. 6 C. 8 D. 10 E. 12

D. Vaporization

What phase transition is indicated by the red arrow in the graph below? A. Sublimation B. Deposition C. Fusion D. Vaporization E. Condensation

A. N2 (g) + 2 O2(g) ⇄ 2 NO2(g); Kc3 = 6.9 x 1035

When the two chemical reactions below are combined together, what is the resulting reaction and its equilibrium constant? N2 (g) + O2 (g) ⇄ 2 NO (g) ; Kc1 = 1 x 1030 2 NO (g) + O2 (g) ⇄ 2 NO2 (g) ; Kc2 = 6.9 x 105 A. N2 (g) + 2 O2(g) ⇄ 2 NO2(g); Kc3 = 6.9 x 1035 B. 2 NO(g) + 2 O2(g) ⇄ 4 NO2(g); Kc3 = 7.9 x 1035 C. N2(g) + 2 O2(g) ⇄ 4 NO2(g); Kc3 = 7.9 x 1035 D. N2(g) + O2(g) + 2 NO(g) ⇄ 4 NO2(g); Kc3 = 7.9 x 1035 E. N2(g) + O2(g) ⇄ 2 NO2(g); Kc3 = 6.9 x 1035

E. Po

Which of the following atom has the lowest first ionization energy? A. O B. S C. Se D. Te E. Po

B. Increasing temperature

Which of the following changes shifts the equilibrium to the left? 2 H2(g) + O2(g) ⇌ 2 H2O(g) ΔH° = -484 kJ/mol A. Decreasing temperature B. Increasing temperature C. Adding H2(g) D. Adding catalyst E. Increasing pressure

B. MgO

Which of the following contains an atom with a 2+ oxidation state? A. NH4+ B. MgO C. H2O2 D. CH4 E. NaCl

E. O2-

Which of the following has the largest atomic radius? A. Mg2+ B. Na+ C. Ne D. F- E. O2-

A. CH3OH

Which of the following is a polar molecule? A. CH3OH B. CCl4 C. BH3 D. C2H6 E. N2

D. HSO3-

Which of the following is the conjugate base for H2SO3? A. H3SO4+ B. HSO4- C. SO3 D. HSO3- E. H2SO4

A. He, N, Cl, O, F

Which of the following is the correct list of elements in order of increasing electronegativity? A. He, N, Cl, O, F B. He, Cl, O, N, F C. He, O, N, F, Cl D. F, O, N, Cl, He E. F, O, N, He, Cl

D. CS2

Which of the following molecules has a zero dipole moment? A. H2O B. NH3 C. CH3Cl D. CS2 E. HF

E. H2SO4 (Ka1 = 1.0 x 103; Ka2 = 1.2 x 10-2)

Which of the following molecules is the strongest acid? A. HCN (Ka = 6.2 x 10-10) B. HNO2 (Ka = 7.2 x 10-4) C. HNO3 (Ka = 2.4 x 101) D. H3PO4 (Ka1 = 7.1 x 10-3; Ka2 = 6.3 x 10-8; Ka3 = 4.2 x 10-13) E. H2SO4 (Ka1 = 1.0 x 103; Ka2 = 1.2 x 10-2)

C. Burette

Which of the following would most accurately measure 10.0 mL of a liquid? A. Beaker B. Erlenmeyer flask C. Burette D. Round bottom flask E. Test Tube