Chem 219: Exam Questions With 100% Correct Answers

Chem 219: Exam Questions With 100% Correct Answers The speed of a wave (c) is the product of its frequency (ν) and wavelength (λ). E = hv = h x c / λ nm to m or m to nm 1 m / 10^9 nm or 10^9 nm / 1 m What is the maximum number of electrons that can have the quantum numbers n = 3, ℓ = 2, mℓ = -2? The Pauli exclusion principle states that no two electrons in a given atom can share the same set of four quantum numbers (n, ℓ, mℓ, ms). This set of quantum numbers contains three quantum numbers, with the only missing quantum number being ms, which can take on the values +½ and -½. Therefore, this set of three quantum numbers represents a single atomic orbital, which can contain two unique electrons: one with ms = +½ and one with ms = -½. An exothermic reaction causes the surroundings to An exothermic reaction transfers energy from the system to the surroundings. That tells us the surroundings will get warmer. A theory is another word for a(n) _________. A theory or model is a well established explanation of a phenomenon based on a series of facts and a body of evidence. What is the definition of a natural law? A scientific law summarizes an observable behavior. The skeletal structure of a complex organic molecule is shown below. Determine the number of sigma (σ) and pi (π) bonds in the molecule. Remember a single bond = 1 σ; a double bond = 1 σ + 1 π; a triple bond = 1 σ + 2 π. This molecule contains 6 double bonds, so there are 6σ and 6π. There are 28 single bonds, so there are 28 σ. This is a total 34σ and 6π. strontium phosphate Sr₃(PO₄)₂ Which of the following statements is true? One driving force in the vaporization of a liquid is an increase in disorder (entropy). Gas molecules are more disordered than liquid molecules. Adding a non-volatile solute to a liquid also increases the disorder of the liquid molecules, so the difference in disorder between the liquid and gas phases is not as great as with a pure substance. Therefore the tendency to vaporize is not as great for the solution as it is for the pure liquid, resulting in a lower vapor pressure for the solution. Which of the following aqueous solutions would have the highest boiling point? A) 1.0 m NaNO3 B) 1.0 m HF C) 1.0 m C₆H₁₂O₆ D) 1.0 m CaCl2 The dissolved solute will raise the boiling point. The more "things" that are dissolved (ions or molecules), the higher the boiling point will be. The CaCl₂ will break up into one Ca²⁺ ion and two Cl⁻ ions and there will be a concentration of 3.0 m of "things" in solution. The other choices will have fewer "things" in solution and will raise the boiling point less. Which one of the following aqueous solutions would have the highest freezing point? A) 1.0 m NaNO3 B) 2.0 m CH3OH C) 1.0 m C₆H₁₂O₆ D) 1.0 m CaCl2 The dissolved solute will lower the freezing point. The more "things" that are dissolved (ions or molecules), the lower the freezing point will be. Since C₆H₁₂O₆ is a molecule, it will not break apart and there will only be a concentration of 1.0 m of molecules in solution. It will lower the freezing point less than all the other choices. There will be fewer "things" in solution and this will lower the freezing point less than the other choices. isoelectronic ions ions containing the same number of electrons Which of the following bonds is the most polar?