Answer:
Explanation:The formula for ammonium carbonate is (NH4)2CO3
The molar mass of ammonium carbonate is 96.1 g/mole
51 g x 1 mole/96.1 g = 0.531 moles (NH4)2CO3
There are TWO moles of NH4+ (ammonium ions) per 1 mole of ammonium carbonate, thus ...
Moles of ammonium ions = 0.531 moles (NH4)2CO3 x 2 moles NH4+/mole (NH4)2CO3 = 1.1 moles NH4+ ions (to 2 sig. figs.)