Question

Compute difference between masses of 1 mole of each of aluminium atom and 1 mole of its ion

Answer 1

Mass of an electron is 9.1×10–28 g). Which one is heavier?

Answer 2

Mass of 1 mole of aluminium atom = the molar mass of aluminium 

= 27 g mol–1 

An aluminium atom needs to lose three electrons to become an ion, Al3+ 

For one mole of A13+ ion, three moles of electrons are to be lost. 

The mass of three moles of electrons = 3 × (9.1×10–28 ) × 6.022×1023 g 

                                                            = 27.3 × 6.022 ×10–5 g 

                                                            = 164.400 ×10–5 g 

                                                            = 0.00164 g 

               Molar mass of Al3+ 

                                                            = (27–0.00164) g mol–1 

                                                            = 26.9984 g mol–1 

                                          Difference = 27 – 26.9984 

                                                           = 0.0016 g