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Chemistry LibreTexts

7.5.2: Practice Stoichiometry part 1

  • Page ID
    236044
  • Mole to Mole Conversions

    Exercise \(\PageIndex{1}\)

    Fe2O3 (s) + 3 CO (g) \(\rightarrow\) 2 Fe (s) + 3 CO2 (g)

    For the reaction above, how many moles of Fe would be produced from 0.877 moles Fe2O3?.

    Answer

    1.75 mol Fe

    How many moles of CO2 would be produced from 0.438 moles Fe2O3?.

    Answer

    1.31 mol CO2

    How many moles of Fe would be produced from 0.545 moles CO?.

    Answer

    0.363 mol Fe

    Mass to Mass Conversions

    Exercise \(\PageIndex{1}\)

    Mg3N2 (s) + 6 H2(l) \(\rightarrow\) 3 Mg(OH)2 (s) + 2 NH3 (g) 

    How many grams of H2O would react with 34.88 grams Mg3N2?

    Answer

    \(34.88 g Mg_3N_2 \times \dfrac{1 mol Mg_3N_2}{100.95 g Mg_3N_2} \times \dfrac{6 mol H_2O}{1 mol Mg_3N_2} \times \dfrac{18.02 g H_2O}{1 mol H_2O}\)

    = 37.36 g H2O

    How many grams of NH3 would be produced from 76.77 grams Mg3N2?.

    Answer

    \(76.77 g Mg_3N_2 \times \dfrac{1 mol Mg_3N_2}{100.95 g Mg_3N_2} \times \dfrac{2 mol NH_3}{1 mol Mg_3N_2} \times \dfrac{17.04 g NH_3}{1 mol NH_3}\)

    = 25.92 g NH3

     How many grams of Mg(OH)2 are produced from 46.32 g H2O?

    Answer

    \(46.32 g H_2O \times \dfrac{1 mol H_2O}{18.02 g H_2O} \times \dfrac{3 mol Mg(OH)_2}{6 mol H_2O} \times \dfrac{58.33 g Mg(OH)_2}{1 mol Mg(OH)_2}\)

    = 74.97 g Mg(OH)2

    Mixed Stoichiometry

    Exercise \(\PageIndex{1}\)

    C3H8 (g) + 5 O2 (g) \(\rightarrow\) 3 CO2 (g) + 4 H2O (g)

    How many grams of O2 are needed to produce 4.22 moles of CO2?

    Answer

    225 grams of O2

    How many moles of C3H8 produce 87.8 grams of H2O?

    Answer

    1.22 moles C3H8

    How many grams of CO2 are produced by a reaction that also produces 2.87 moles H2O?

    Answer

    94.7 g CO2

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