Molar Conversion

Converting Between Moles and Mass
- to convert between moles and mass we use molar mass as the conversion factors
- BE SURE TO CANCEL THE APPROPRIATE UNITS

Examples:

How many grams are there in 2.5 mole of P4  (  F2 : 19.0 x 2 = 38)

Step 1: 2.5 mol                         g   =         g
                                             mol
Step 2: 2.5mol          38.0          g  =    95 g  
                                  1         mol

Remember!!!!!
            -significant digits
            -0 is NEVER a significant digit
            - balance chemical equations first

A compound is made of phosphorous and chlorine. It is found to contain 0.200 mol and has a mass of 27.5
- determine molar mass of the compound
- suggest possible formula

27.5 g         = 137.5 g/mol
0.200 mol 

PxCly:       X              Y       MOLAR MASS
                  1              2                  102
                  2              1                 97.5
                  2              2                 133
                  1              3                 137.5                  
Phosphorous and chlorine = PCl3

Nicole H