What is the name and formula for the compound formed from magnesium, 2+, and phosphide, 3-, ions?

1 Answer
Jan 12, 2017

Answer:

#"Magnesium phosphide........."#

Explanation:

And to form the salt, we draft in anions and cations to form a neutral entity, i.e. here #Mg_3P_2#........This would be nasty stuff; so if you have an old, unopened bottles lurking in the back of a cupboard exercise due care. Of course, an opened bottle might have hydrolyzed long ago....

So how did I know the formula was #Mg_3P_2#? Well, the constituent ions are #Mg^(2+)# and phosphide, #P^(3-)#. The salt MUST be electrically neutral, so we cross mulitply to give #2xxP^(3-)+3xxMg^(2+)=Mg_3P_2#. Capisce?