Question

1. How many MOLECULES of dinitrogen tetrafluoride are present in 1.63 grams of this compound? _____ molecules.

2. How many GRAMS of dinitrogen tetrafluoride are present in 6.59×1022 molecules of this compound? _____ grams.

Answer 1

1)

mass of N2F4 = 1.63 g

moles of N2F4 = 1.63 / 104 = 0.01567 mol

1 mol   --------------> 6.023 x 10^23 molecules

0.01567 mol ---------> ??

number of molecules = 0.0157 x 6.023 x 10^23

                                   = 9.44 x 10^21 molecules

2)

number of molecules = 6.59×10^22 molecules

moles = 6.59×10^22 / 6.023 x 10^23

           = 0.1094 mol

mass of N2F4 = 0.1094 x 104 = 11.4 g

mass of N2F4 = 11.4 g