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Molarity: Flashcards

Revise molarity, making and diluting solutions, and solution stoichiometry.

10 cardsIntermediate

10 cards

  1. Question
    What is molarity?
    Answer

    Moles of solute per litre of solution (unit mol/L, written M).

  2. Question
    How do you find moles from molarity and volume?
    Answer

    moles = molarity × volume (in litres)

  3. Question
    What does 0.250 M mean?
    Answer

    0.250 mol of solute in every litre of solution.

  4. Question
    What is the dilution equation?
    Answer

    M1V1=M2V2M_1 V_1 = M_2 V_2, because the moles of solute stay the same.

  5. Question
    How many moles of solute are in 250.0 mL of 0.400 M solution?
    Answer

    0.400×0.2500=0.1000.400 \times 0.2500 = 0.100 mol

  6. Question
    10.0 mL of 12.0 M HCl is diluted to 250.0 mL. What is the new concentration?
    Answer

    12.0×10.0250.0=0.480\dfrac{12.0 \times 10.0}{250.0} = 0.480 M

  7. Question
    Why must you convert mL to L in molarity calculations?
    Answer

    Molarity is per litre. Using mL makes the answer 1000 times wrong.

  8. Question
    What is the difference between the solute and the solvent?
    Answer

    The solute is the substance dissolved; the solvent is what it dissolves in (often water).

  9. Question
    What is a titration?
    Answer

    A method that measures the exact volume of one solution needed to react with another, used to find an unknown concentration.

  10. Question
    What does the symbol [NaCl] mean?
    Answer

    The concentration of NaCl, in mol/L.