genchem8

    Cards (25)

    • What happens to substances in a chemical reaction?

      A substance (or substances) is converted to one or more new substances.
    • What does the law of conservation of mass state?
      No atoms are created or destroyed; they are just rearranged.
    • How do chemists communicate chemical reactions?
      They represent chemical reactions through chemical equations.
    • Where are reactants placed in a chemical equation?
      Reactants are placed on the left side.
    • Where are products placed in a chemical equation?
      Products are placed on the right side.
    • What does the arrow in a chemical equation indicate?
      An arrow points towards the direction of the reaction.
    • Why must a chemical equation be balanced?
      To ensure the same number and types of atoms appear on both sides of the equation.
    • What are coefficients in a chemical equation?
      Coefficients are numbers preceding the chemical formula used to balance the equation.
    • What are reactants in a chemical reaction?
      • Compounds or elements needed in the reaction
      • Undergo chemical change during the reaction
    • What does "yield" mean in chemical reactions?
      • Means to "produce" or "form"
      • Usually represented by an arrow
    • What are products in a chemical reaction?
      • End results of the reaction
      • Compounds produced in a chemical reaction
    • What are the different styles of yields arrows in chemical equations?
      1. Forward arrow (→) - general reaction
      2. Equilibrium arrow (⇌) - reversible process
      3. Resonance arrow (↔) - resonance structures
      4. Theoretical arrow (⇢) - theoretical process
      5. Retrosynthetic arrow (⇒) - potential pathways from reactants to products
    • What do subscripts in a chemical formula represent?
      Subscripts represent how many atoms of each element are present in a molecule.
    • What do coefficients represent in a chemical reaction?
      Coefficients represent how many molecules of a specific chemical compound are present in the reaction.
    • What is a combination reaction?
      • Also known as a synthesis reaction
      • Two or more substances combine to form a single new substance
      • General form: A + BAB
    • Give an example of a combination reaction.
      2Na(s) + Cl2(g) → 2NaCl(s)
    • What is a decomposition reaction?
      • A reaction in which a compound breaks down into two or more simpler substances
      • General form: ABA + B
    • Give an example of a decomposition reaction.
      2HgO(s) → 2Hg(l) + O2(g)
    • What is a single-replacement reaction?
      • A reaction in which one element replaces a similar element in a compound
      • General form: A + BCAC + B
    • What is a double-replacement reaction?
      • A reaction in which the positive and negative ions of two ionic compounds exchange places
      • General form: AB + CDAD + CB
    • What is a combustion reaction?
      • A reaction in which a substance reacts with oxygen gas
      • Releases energy in the form of light and heat
      • Must involve O2 as one reactant
    • What is the first rule in balancing chemical formulas?
      Identify reactants and products and write their correct formulas.
    • What is the second rule in balancing chemical formulas?
      Balance the equation by changing the coefficients of the reactants or products.
    • What is the third rule in balancing chemical formulas?
      Check to make sure that the number of each type of atom is the same on each side of the equation.
    • What are the steps in balancing chemical formulas using the algebraic method?
      1. Assign unknown coefficients with letters.
      2. Equate the number of participating elements in both sides.
      3. Substitute the equivalent number of first coefficient to the next equation.
      4. If values are in fraction, choose a number to multiply to become a whole number.
      5. Replace letter coefficients with these values after getting the whole number ratio.
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