Question

Calculate the amount (in mole) of:
Cl- ions in 13.4g of nickel chloride (NiCl2)

Answer 1

For solving this task you need to use next :
molecule of NiCl2 consisted of one atom of Ni and two atoms of Cl,so
& 13.4g n
& NiCl2 --------------->2Cl-
129 2

n=13.4*2/129=0.208 mol