Chemistry:problems and solutions 1

1.   Determine the hybridization scheme used by the underlined atom in each of the molecules below. (a)  CO2 2 bonding groups, 0 lone pairs on carbon linear electron geometry Þ sp hybrid orbitals (b)  CH2O 3 bonding groups, 0 lone pairs on carbon trigonal planar electron geometry Þ sp2 hybrid orbitals (c)  SeF4 4 bonding […]

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Chemistry:isotopes questions with answers

Gallium consists of two isotopes of masses 68.95amu and 70.95amu with abundance of 60.16% and 39.84%, respectively.  What is the average atomic mass of gallium? ( Ans: ca.  69.75) Naturally occurring cupper exists in two isotopic forms: 63Cu and 65Cu.  The atomic mass of copper is 63.55amu.  What is the approximate abundance of 63Cu? (Ans: […]

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Chemistry:stoichiometry questions 2

1.         Zinc and sulfur react to form zinc sulfide according to the following eqn. 8 Zn(s)   +  S8(s)   –à   8 ZnS If 2.00 mol of Zn are heated with 1.00 mol of S8, identify the limiting reagent. How many moles of excess reactant remain How many moles of the product are formed? 2.         Carbon reacts […]

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