{
  "id": "a5169410-2332-5398-8a1f-9857dd869801",
  "slug": "r1-4-entropy-and-spontaneity",
  "title": "R1.4 Entropy and spontaneity",
  "course": "IB Chemistry",
  "level": "HL",
  "syllabusCode": "R1.4",
  "questionCount": 14,
  "page": "https://splycr.com/ib-chemistry/r1-4-entropy-and-spontaneity",
  "data": "https://splycr.com/library/r1-4-entropy-and-spontaneity.json",
  "play": "https://splycr.com/?set=a5169410-2332-5398-8a1f-9857dd869801",
  "section": {
    "name": "Reactivity 1: What drives chemical reactions?",
    "page": "https://splycr.com/ib-chemistry/what-drives-chemical-reactions"
  },
  "source": {
    "name": "Biology by Bradford",
    "href": "https://www.biologybybradford.com",
    "note": "Written for the splycr library by Biology by Bradford."
  },
  "questions": [
    {
      "number": 1,
      "question": "Measure of the dispersal of energy and matter in a system?",
      "answer": "Entropy",
      "wrongOptions": [
        "Enthalpy",
        "Gibbs energy",
        "Activation energy"
      ]
    },
    {
      "number": 2,
      "question": "Units of standard entropy, S⦵?",
      "answer": "J K⁻¹ mol⁻¹",
      "wrongOptions": [
        "kJ mol⁻¹",
        "J mol⁻¹",
        "K J⁻¹ mol⁻¹"
      ]
    },
    {
      "number": 3,
      "question": "State of a substance with the highest entropy?",
      "answer": "Gas",
      "wrongOptions": [
        "Liquid",
        "Solid",
        "Aqueous solution"
      ]
    },
    {
      "number": 4,
      "question": "Which change gives the largest increase in entropy?",
      "answer": "H₂O(l) → H₂O(g)",
      "wrongOptions": [
        "H₂O(g) → H₂O(l)",
        "H₂O(s) → H₂O(l)",
        "N₂ + 3H₂ → 2NH₃"
      ]
    },
    {
      "number": 5,
      "question": "Sign of ΔS for CaCO₃(s) → CaO(s) + CO₂(g)?",
      "answer": "Positive",
      "wrongOptions": [
        "Negative",
        "Zero",
        "Cannot tell"
      ]
    },
    {
      "number": 6,
      "question": "Expression for ΔS⦵ from standard entropies?",
      "answer": "ΣS⦵(products) − ΣS⦵(reactants)",
      "wrongOptions": [
        "ΣS⦵(reactants) − ΣS⦵(products)",
        "ΣS⦵(products) + ΣS⦵(reactants)",
        "ΣS⦵(products) ÷ ΣS⦵(reactants)"
      ]
    },
    {
      "number": 7,
      "question": "For a spontaneous process, the total entropy of the universe…?",
      "answer": "Increases",
      "wrongOptions": [
        "Decreases",
        "Stays constant",
        "Becomes zero"
      ]
    },
    {
      "number": 8,
      "question": "Equation for the Gibbs energy change?",
      "answer": "ΔG = ΔH − TΔS",
      "wrongOptions": [
        "ΔG = ΔH + TΔS",
        "ΔG = TΔS − ΔH",
        "ΔG = ΔS − TΔH"
      ]
    },
    {
      "number": 9,
      "question": "Sign of ΔG for a spontaneous reaction?",
      "answer": "Negative",
      "wrongOptions": [
        "Positive",
        "Zero",
        "Either sign"
      ]
    },
    {
      "number": 10,
      "question": "Value of ΔG for a reaction mixture at equilibrium?",
      "answer": "Zero",
      "wrongOptions": [
        "Positive",
        "Negative",
        "Equal to ΔH"
      ]
    },
    {
      "number": 11,
      "question": "A reaction with ΔH < 0 and ΔS > 0 is spontaneous…?",
      "answer": "At all temperatures",
      "wrongOptions": [
        "At no temperature",
        "Only at high temperature",
        "Only at low temperature"
      ]
    },
    {
      "number": 12,
      "question": "A reaction with ΔH > 0 and ΔS > 0 becomes spontaneous…?",
      "answer": "At high temperature",
      "wrongOptions": [
        "At low temperature",
        "At all temperatures",
        "At no temperature"
      ]
    },
    {
      "number": 13,
      "question": "ΔH = +100 kJ mol⁻¹, ΔS = +200 J K⁻¹ mol⁻¹. Temperature above which it is spontaneous?",
      "answer": "500 K",
      "wrongOptions": [
        "0.5 K",
        "50 K",
        "2000 K"
      ]
    },
    {
      "number": 14,
      "question": "ΔG at 300 K when ΔH = −50 kJ mol⁻¹ and ΔS = −100 J K⁻¹ mol⁻¹?",
      "answer": "−20 kJ mol⁻¹",
      "wrongOptions": [
        "−80 kJ mol⁻¹",
        "+20 kJ mol⁻¹",
        "+29 950 kJ mol⁻¹"
      ]
    }
  ]
}