Moles, mass and gas calculations

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Intros
Lessons
  1. Using mass and gas volume in stoichiometry calculations
  2. Recap stoichiometry basics
  3. Calculating moles
  4. Molar volume of gas and Avogadro's law.
  5. Worked example: using molar volume and unit conversions
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Examples
Lessons
  1. Calculate the masses and volumes of reactants and products used in chemical reactions.
    Consider the reaction:

    2C6_6H14β€…β€Š(l)+_{14\;(l)} +19O2β€…β€Š(g)_{2\;(g)} \enspace \enspace 12CO2β€…β€Š(g)+_{2\;(g)} + 14H2_2Oβ€…β€Š(g)_{\;(g)}

    1. If 75g of C6_6H14_{14} is burned, what mass of CO2_2 would get produced from this reaction?
    2. If 240g of H2_2O is produced from this reaction, how many moles of C6_6H14_{14} would be required?
    3. At STP, what volume of O2_2 would be required to produce 85 L of CO2_2 in this process?
    4. What mass of C6_6H14_{14} would be required to produce 15 moles of CO2_2?
  2. Calculate the masses and volumes of reactants and products used in chemical reactions.
    Consider the reaction:

    P4β€…β€Š(s)+_{4\;(s)} + 5O2β€…β€Š(g)_{2\;(g)} \enspace \enspace P4_4O10β€…β€Š(s)_{10\;(s)}

    1. At STP, what volume of O2_2 gas is needed to completely combust 2kg of P4_4?
    2. If 25 L of O2_2 were available, how much mass of P4_4 could be reacted with?
    3. What mass of P4_4O10_{10} would be produced by this?
  3. Calculate the volume and number of moles of reactants involved in chemical reactions.
    Consider the reaction:

    2NH3β€…β€Š(aq) + _{3\;(aq)} \,+ \, NaOClβ€…β€Š(aq)_{\;(aq)} \enspace \enspace N2_2H4β€…β€Š(aq) + _{4\;(aq)} \,+ \, NaClβ€…β€Š(aq) + _{\;(aq)} \,+ \, H2_2Oβ€…β€Š(l)_{\;(l)}

    1. If 5000 kg of hydrazine (N2_2H4_{4}) is required from this industrial process, how much ammonia gas (in L completely dissolved in solution at STP) is required as starting material?
    2. How many moles of hydrazine could be produced if only 5 kg of NaOCl was available?
  4. Calculate the volume of reactants required in a chemical process.
    Consider the reaction:

    SiCl4β€…β€Š(g) + _{4\;(g)} \, + \, 2H2β€…β€Š(g)_{2\;(g)} \enspace \enspace Siβ€…β€Š(s) + _{\;(s)} \, + \, 4HClβ€…β€Š(g)_{\;(g)}


    500 mg of Si is required from this process. What is the total volume, in L, of H2_2 and SiCl4_4 required to produce this?