Ammonium iron(III) citrate has these ions in its formula: • more than one ammonium ion • one iron ion • two $\text{C}_6\text{H}_4\text{O}_7^{4-}$ ions. What is the chemical formula of ammonium iron(III) citrate?
- A$(\text{NH}_4)_4\text{Fe}(\text{C}_6\text{H}_4\text{O}_7)_2$
- B$(\text{NH}_4)_5\text{Fe}(\text{C}_6\text{H}_4\text{O}_7)_2$
- C$(\text{NH}_4)_6\text{Fe}(\text{C}_6\text{H}_4\text{O}_7)_2$
- D$(\text{NH}_4)_7\text{Fe}(\text{C}_6\text{H}_4\text{O}_7)_2$