Chem #2

  1. Calculate the molecular or formula mass of rubidium carbonate, Rb2CO3
    230.94 g/mol
  2. Aluminum sulfate, Al2(So4)3, is used in tanning leather, purifying water, and manufacture of antiperspirants. Calculate its molecular or formula mass.
    342.15 g/mol
  3. What is the percent carbon in CH3 CH2 OH?
  4. Balance the following equation:
    UO2(s) + HF(l)---->UF4(s) + H2O
    UO2(s) + 4HF(l)----->UF4(s) + 2H20(l)
  5. Balance the following equation:
    C8H18O3(l) + O2(g)---->H2O(g) + CO2(g)
    C8H18O3(l) + 11O2(g)-----> 9H20(g) + 8CO2(g)
  6. Balance the following equation:
    Ca3(PO4)2(s) + SiO2(s) + C(s)----->CaSiO3(s) + CO (g) + P4(s)
    2Ca3(PO4)2(s) + 6SiO2(s) + 10 C(s)----->6CaSiO3(s) + 10CO(g) + P4(s)
  7. What is the coefficient of H2SO4 when the following equation is properly balanced with the smallest set of whole numbers?
    __Ca3(PO4)2 +___H2SO4 ----> ___CaSO4 + ___H3PO4
  8. Balance the following equation using the smallest set of whole numbers, then add together the coefficients. Don't forget to count coefficients of one. The sum of the coefficients is
    ___SF4 + ___H2O ----> ___H2SO3 +___HF
  9. Calculate the number of moles in 17.8 g of the antacid magnesium hydroxide, Mg(OH)2
    0.305 mol
  10. Phosphorus pentachloride, a white solid that has a pungent, unpleasant odor, is used as a catalyst for certain organic reactions. Calculate the number of moles in 38.7 g of phosphorus pentachloride.
    0.186 mol
  11. Aluminum oxide, Al2 O3, is used as a filler for paints and varnishes as well as in the manufacture of electrical insulators. Calculate the number of moles in 47.51g of Al2 O3.
    0.4660 mol
  12. A compound containing chromium and silicon contains 73.52 mass percent chromium. Determine its empirical formula
    Cr3 Si2

    100.00L - 73.52= 16.48
  13. Sulfur dioxide reacts with chlorine to produce thionyl chloride (used as a drying agent for inorganic halides) and dichlorine oxide (used as a bleach for wood, pulp and textiles).
    SO2(g) + 2Cl2 (g) -----> SOCl2 (g) + Cl2O (g)

    If 0.400 mol of Cl2 reacts with excess SO2, how many moles of Cl2O are formed?
    0.200 mol

    .4mol Cl2 x 1mol O2/2 mol Cl = .2m
  14. Aluminum will react with bromine to form aluminum bromide (used as an acid catalyst in organic synthesis).
    Al(s) + Br2 (l)----->Al2Br6 (s) (unbalanced)
    2 3

    How many moles of Al are needed to form 2.43 mol of Al2Br6?
    4.86 mol

    2.43 mol Al2Br6 x 2mol Al/1mol Al2Br6
  15. Ammonia will react with flourine to produce dinitrogen tetrafluoride and hydrogen flouride (used in production of aluminum, in uranium processing, and in frosting of light bulbs)

    2NH3(g) + 5F2 (g)-----> N2F4 (g) + 6HF (g)
    How many moles of NH3 are needed to react completely with 1.6 mol of F2?
    5.44 mol
  16. How many grams of nitrogen are requires to react with 2.79g of hydrogen to produce ammonia?
    13.0 g

    • N2 + 3H2----> 2NH3
    • 2.79gH2 x 1mol H2/2.79g x 1molN2/3molH2 x 28gN2/1molN2
  17. Phosphine, an extremely poisonous and highly reactive gas, will react with oxygen to form tetraphosphorus decaoxide and water (balance the equation)
    PH3 (g) + O2 (g)-----> P4O10(s) + H2O (g)
    Calculate the mass of P4O10(s) formed when 225g of PH3 reacts with excess oxygen.
  18. Hydrochloric acid can be prepared by the following reaction:
    2NaCl(s) + H2So4(aq)---->4HCl (g) + Na2SO4 (s)
    How many grams of HCl can be prepared from 2.00 mol H2SO4 and 150g NaCl?
  19. What is the limiting reactant when 13.9g of oxygen react with 33.7g of calcium to produce calcium oxide and how many grams of calcium oxide are produced?
    Calcium is the limiting reactant and 47.1g of calcium oxide are produced
  20. Tetrasulfur dinitride decomposes explosively when heated. What is it's formula?
  21. How many grams of water could be made from 5.0 mol H2 and 3.0 mol O2?
    90 g
  22. what is the limiting reactant when 3.41g of nitrogen react with 2.79g of hydrogen to produce ammonia and how many grams of ammonia are produced?
    Nitrogen is the limiting reactant and 4.15g of ammonia are produced.
Card Set
Chem #2
balancing equations, molecular mass