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GOB Chemistry: Chemical Quantities and Reactions

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Terms in this set (20)

  • What is Avogadro's number and what does it represent?
    Avogadro's number is \(6.02 \times 10^{23}\) and it represents the number of particles (atoms, molecules, or ions) in one mole of a substance.
  • How many atoms are in 1 mole of carbon?
    1 mole of carbon contains \(6.02 \times 10^{23}\) atoms of carbon.
  • What is the molar mass of an element?
    The molar mass is the mass in grams of 1 mole of an element, numerically equal to the atomic mass but expressed in grams.
  • How do you calculate the molar mass of a compound like Li2CO3?
    Multiply the molar mass of each element by its subscript in the formula and sum the results: 2 Li, 1 C, and 3 O atoms.
  • What is the relationship between grams and moles for a substance?
    Molar mass acts as a conversion factor between grams and moles: \(\frac{grams}{mole}\).
  • How do you convert moles of a compound to moles of an element within it?
    Use the subscript of the element in the chemical formula as a conversion factor (e.g., 9 moles of C per 1 mole of C9H8O4).
  • What is a balanced chemical equation?
    An equation where the number of atoms of each element is equal on both reactant and product sides, with no atoms lost or gained.
  • What are the steps to balance a chemical equation?
    Write correct formulas, count atoms, use coefficients to balance elements, and verify the final balanced equation.
  • What is oxidation in a chemical reaction?
    Oxidation is the loss of electrons by a substance.
  • What is reduction in a chemical reaction?
    Reduction is the gain of electrons by a substance.
  • What is the mnemonic to remember oxidation and reduction?
    OIL RIG: Oxidation Is Loss, Reduction Is Gain of electrons.
  • In the reaction Zn(s) + CuSO4(aq) → ZnSO4(aq) + Cu(s), which is oxidized and which is reduced?
    Zn is oxidized (loses electrons), Cu2+ is reduced (gains electrons).
  • What is an oxidizing agent?
    The substance that gains electrons and causes another to be oxidized.
  • What is a reducing agent?
    The substance that loses electrons and causes another to be reduced.
  • What is an exothermic reaction?
    A reaction that releases heat, with products having less energy than reactants.
  • What is an endothermic reaction?
    A reaction that absorbs heat, with products having more energy than reactants.
  • What are the three conditions required for a chemical reaction to occur?
    1. Reactants must collide, 2. Proper orientation, 3. Sufficient activation energy.
  • How does temperature affect reaction rate?
    Increasing temperature increases reaction rate by causing more frequent and energetic collisions.
  • What is the role of a catalyst in a chemical reaction?
    A catalyst increases the reaction rate by lowering the activation energy without being consumed.
  • How does concentration affect the rate of reaction?
    Increasing the concentration of reactants increases the reaction rate by increasing collision frequency.