Question #5c707

1 Answer
Jul 5, 2016

Here's how you can do that.

Explanation:

Ammonium phosphate, #("NH"_color(red)(4))_color(blue)(3)"PO"_4#, is an ionic compound made up of ammonium cations, #"NH"_4^(+)#, and phosphate anions, #"PO"_4^(3-)#.

As you can see from the compound's chemical formula, one formula unit of ammonium phosphate contains

  • three ammonium cations, #color(blue)(3) xx "NH"_4^(+)#
  • one phosphate anion, #1 xx "PO"_4^(3-)#

http://www.wikiwand.com/en/Ammonium_phosphate

This of course means that one mole of ammonium phosphate will contain #color(blue)(3)# moles of ammonium cations and #1# mole of phosphate anions.

Now, each ammonium cation is made up of

  • one atom of nitrogen, #1 xx "N"#
  • four atoms of hydrogen, #color(red)(4) xx "H"#

Since one mole of ammonium cations will contain #color(red)(4)# moles of hydrogen atoms, it follows that one mole of ammonium phosphate will contain a total of

#color(blue)(3) color(darkred)(cancel(color(black)("moles NH"_4^(+)))) * (color(red)(4)color(white)(a)"moles of H")/(1color(darkred)(cancel(color(black)("mole NH"_4^(+))))) = color(green)(|bar(ul(color(white)(a/a)color(black)("12 moles of H")color(white)(a/a)|)))#

Therefore, you can say that every mole of ammonium phosphate contains a total of #12# moles of hydrogen atoms.

You can expand this to say that for any number of moles of ammonium chloride given to you, #n#, the number of moles of hydrogen atoms can be found by multiplying #n# by #12#

#n color(red)(cancel(color(black)("moles"color(white)(a)("NH"_4)_3"PO"_4))) * "12 moles H"/(1color(red)(cancel(color(black)("mole"color(white)(a)("NH"_4)_3"PO"_4)))) = (12 * n)color(white)(a)"moles H"#