Chemistry                                Quiz #2

 

 

  1. (2 pt)  How many moles of carbon are contained in 36.0 grams of CO2?

 

Molar mass of CO2 = mass of carbon + 2 * mass of oxygen

        = 12.011 g/mol + 2 * 16.00 g/mol

        = 44.011 g/mol

 

36.0 g CO2 * 1 mol CO2  = 0.818 mol CO2

                       44.011 g CO2

 You then need to recognize that there is 1 C in ever CO2.

 

0.818 mol CO2 * 1 mol C  = 0.818 mol C

                            1 mol CO2

 

  1. (5 pt.)  I have 27.05 grams of nickel (IV) bromide, how many moles is that?

 

  NiBr4  has a molar mass = molar mass of nickel + 4* molar mass of bromine

                                        = 58.693 g/mol + 4 * 79.904 g/mol

                                        = 379.3 g/mol

 

27.05 g NiBr4  * 1 mol NiBr4 = 0.0715 mol NiBr4

                           379.3 g NiBr4

 

  1. (8 pt)  Fill in the blanks in the chart below.

 

 

Compound                                    Name

SnCl2                                 tin (II) chloride

 

CuBr2                                copper (II) bromide

 

CS2                                    carbon disulfide

 

N­2O5                                  dinitrogen pentoxide

 

CuF2                                  copper (II) fluoride

 

CaO                                   calcium oxide  [(II) isn’t necessary for alkali earth metals)

 

NiI4                                   nickel (IV) iodide

 

Fe2O3                                 iron (III) oxide