Ammonium iron(II) sulfate (Mohr's salt) is a double salt commonly used as a primary standard in redox titrations because of its high stability against oxidation in air.
Which of the following lists all the chemical elements present in anhydrous ammonium iron(II) sulfate?
hydrogen, iron, nitrogen and oxygen only
hydrogen, iron, nitrogen and sulfur only
hydrogen, iron, nitrogen, oxygen and sulfur only
iron, nitrogen, oxygen and sulfur only