CHE 101 Exam 1 Notes

Exam Structure

  • Exam Name: CHE 101 Exam 1, Spring 2025
  • Total Points: 100
    • Section 1: Multiple Choice (48 points total, 3 points each)
    • Section 2: Full Answer (52 points total)

Multiple Choice Questions

Physical Changes of Matter
  • Example of Physical Change:
    • b. Melting of ice (H2O (s))
    • e. Expansion of gaseous nitrogen (N2 (g))
Significant Figures
  • Numbers with 3 Significant Figures:
    • b. 2.50
    • c. 205.0
Speed of Light and Distance
  • Speed of light: 1.08 × 10^9 km/h
  • Distance to Jupiter: 4.84 × 10^8 miles
  • Time for light to reach Jupiter:
    • b. 16.7 minutes
Monatomic Ions
  • Correct Pairings of Elements and Their Ions:
    • a. sulfur: S2-
    • c. sodium: Na+
    • e. magnesium: Mg2+
Covalent and Ionic Compounds
  • Covalent Compounds:
    • a. P2O5
    • d. As4O10
  • Ionic Compounds:
    • a. MgCl2·6H2O
    • b. Fe(NO2)2
    • d. NH4ClO4
Samples with Highest Moles of Ions
  • Higher Moles of Ions:
    • a. 1.5 mol Ca(OH)2 (produces 3 moles of ions)
Atoms of Oxygen in Moles
  • Atoms of Oxygen in 6.38 mol of Cs2CrO4:
    • c. 7.68 × 10^24 atoms
Single Replacement Reactions
  • Sets of Reactants for Single Replacement:
    • a. Cr(s) + CuCl2(aq)
    • b. Zn(s) + H2SO4(aq)
Non-Electrolytes
  • Non-Electrolyte Compounds:
    • a. SF6
Molarity Calculations
  • Molarity of Sucrose (C12H22O11):
    • c. 1.369 M
      (Calculated from mass of 150.0 g in 250.0 mL)
Neutralization Reaction Volume
  • Volume of HBr required for Neutralization:
    • b. 100.0 mL
Balancing Chemical Equations
  • Combustion Reaction of Methane:
    • Limiting reactant: a. CH4
    • Percentage yield with 0.60 mol CO2: d. 60%

Full Answer Questions

Classifying Samples
  • Types of matter classification samples:
    • Air: A (Homogeneous mixture)
    • Dirt: B (Heterogeneous mixture)
    • N2(g): C (Element)
    • Na2SO4 (aq): D (Compound)
Scientific Notation Conversion
  • Provide scientific notation equivalent for standard notation entries.
Subatomic Particles Information
  • Charge and Mass:
    • Electron: -1.602 × 10^-19 C, 0.00054858 amu
    • Proton: +1.602 × 10^-19 C, 1.0073 amu
    • Neutron: 0 C, 1.0087 amu
Isotopes Information
  • Example Isotope Information:
    • For 12C^{12}C: Number of protons: 6, Neutrons: 6
  • Atomic Weight Calculation:
    • From provided natural abundances and atomic mass information.
Empirical and Molecular Formula Calculations
  • Empirical Formula from Mass Percentage:
    • Calculate based on given mass percentages of C, H, N, and O.
Reaction Types Classification
  • Types of reactions to identify:
    • Combustion, single displacement, double displacement, decomposition, synthesis.
Mass Production in Reactions
  • Calculating mass of products from given reactants to find mass of NH3 produced from N2.
Ionic Reaction Equations
  • Provide molecular, full ionic, and net ionic equations for reactions mentioned (FeCl3 + Na2CO3, HCN + LiOH).