Sodium/natrium is a metal from first column group so it should have one 1+ charge. Phosphate ion has 3- charge. That is why there 3 natrium ion for 1 phosphate ion when this molecule is dissolved in water. The ion formula would be:
(Na)

(PO

) ==> 3 Na

+ PO
Answer:
I dont lnow much about chemistry, but I believe it's either d or a. sorry if its wrong!
Answer:-
2747.7 Cal mol -1
Explanation:-
Molar heat of Fusion is defined as the amount of heat necessary to melt (or freeze) 1 mole of a substance at its melting point.
Atomic mass of Iron = 55.845 g mol-1
Mass of Iron = 200 g
Number of moles of Iron = 200 g / (55.845 g mol-)
= 3.581 moles
Heat released = 9840 Cal
Molar heat of Fusion = Heat released / Number of moles
= 9840 Cal / 3.581 moles
= 2747.7 Cal mol -1