Chemistry Concepts Quiz

Exam Instructions

• The exam has 28 questions, each worth 1 point.
• It's a closed-book exam; notes, papers, and electronic devices are not allowed.
• Do not turn the pages before instructed.
• Do not continue writing after instructed to stop.
• Answer in the designated area; answers outside the area may not be graded.
• For multiple choice, use a pencil to fully darken the bubble. Erase completely if needing to change an answer. Only bubble one answer per question. Unbubbled or incorrect bubbles may not receive credit.

Chemistry Concepts (Page 2)

• Significant Figures: Calculation 16 + 33.35 / 5.2 = 9.5
• Periodic Table: Nonmetals are not limited to Groups 1 and 2. Elements in the same group share similar properties. Noble gases (Group 18) are largely inert under normal conditions. Transition metals are in the center (Groups 3-12).
• Electrolytes: Strong electrolytes completely dissociate into ions in water, weak electrolytes partially dissociate, and higher concentrations of non-electrolytes don't increase conductivity. Conductivity depends on the extent of ionization/dissociation.
• Plane Descent: A plane descending at 2200 feet per minute descends 72 meters in one second. (2,200 feet/min * 1min/60sec* 0.3048meters/foot = 11 meters/sec)

Chemistry Concepts (Page 3)

• Chemical Compounds: Fe₂O₃ is Iron (III) oxide, PCl₅ is Phosphorus pentachloride.
• Moles of Oxygen: 1.00 × 10²⁷ 0₂ molecules contain 1.66 × 10²³ oxygen atoms. (1.00 x 10^27 molecules * 2 atoms O/ molecule * 1.66 X 10^-23 atoms/ mol)
• Empirical Formula: A compound with 82.66% carbon and 17.34% hydrogen has an empirical formula of C₂H₄.

Chemistry Concepts (Page 4)

• Mass of Water: 15.0 g of O₂ results in the formation of 16.9 g of water. (15g O2/ 16g O2/mole O2/2 moles H2)
• Limiting Reactants: Insufficient information is provided to determine the limiting reactant in a reaction of 15.0 grams of sulfuric acid mixed with 20.0 grams of potassium hydroxide.
• Sodium Carbonate: In the reaction of 35.0 g of CO₂ and 95.0 g of NaOH, 84.3 g of sodium carbonate will be produced.
• Scuba Diving: Ascent can impact lung pressure; the volume of air increases.

Chemistry Concepts (Page 5)

• Pressure Change: A 1.0-L reactor with an initial internal pressure of 350.0 psi at 27.0 °C will have a pressure of 458 psi at 120 °C.
• Oxygen Gas Pressure: The pressure in a 3.35-L reactor with filled with 6.00 moles of oxygen gas at 27.0 °C is 44.1 atm.
• Nitrogen Volume: A reaction of 32.00 kg of hydrazine (N₂H₄) and 36.00 kg of oxygen (O₂) produces a total volume of nitrogen of 5.77 x 10³ L.
• IV Injection: 150 mg of the drug requires 0.30 L of the IV pack.

Chemistry Concepts (Page 6)

• Solubility Rules: Most alkali metal and ammonium compounds are soluble; nitrates and acetates are generally soluble. Most sulfates are soluble, with exceptions. Chlorides, bromides, and iodides are mostly soluble, with a few exceptions. Silver compounds (except AgNO₃ and AgClO₄) are mostly insoluble. Oxides and hydroxides are mostly insoluble, with exceptions for alkali metals and some alkaline earth metals. Sulfides are mostly insoluble, with exceptions. Chromates are mostly insoluble, and carbonates, phosphates, sulfites, and silicates are usually insoluble, with exceptions for Na+, K+, and NH₄+.
• Reaction of Ions: Ag+, NO₃⁻, K⁺, Cl⁻ ions in solution will NOT react.

Chemistry Concepts (Page 7)

• Equilibrium Constant: The equilibrium constant (K) expression for a reaction may vary based on the balanced equation. The addition of a catalyst will not change the equilibrium constant in a chemical equation.
• Methanol Synthesis: The synthesis of methanol through a reversible reaction can be influenced by changing the temperature, volume, and reactant concentration.
• Acids and Bases: In the reaction of HPO4⁻(aq) + H₂O(l) = H₂PO₄⁻ (aq) + OH⁻(aq), the H₂PO₄⁻ is the conjugate acid of the HPO4⁻2. The HPO4⁻2 acts as a Brønsted-Lowry base.

Chemistry Concepts (Page 8)

• Acid Ionization Constant: Different acids have different acid ionization constants (Kₐ values). A stronger acid has a larger Kₐ value. Polyprotic acids (like carbonic acid) often have successively smaller Kₐ values for the stepwise loss of protons. Water concentration is not included in the calculations of Kₐ.
• Hydroxide Concentration: A solution with pH 4.53 at 25 °C has a hydroxide concentration of 3.0 x 10⁻¹⁰ M.

Test your understanding of significant figures, the periodic table, and electrolytes in this chemistry concepts quiz. Each question will challenge your knowledge and application of these foundational topics. Prepare to demonstrate your skills in a closed-book format.