Question

Question14 of 20If 5.15 g FeCl3 is dissolved in enough water to make exactly 150.0 mL of solution, what is the molar concentration of chloride ion? The formula weight of FeCl3 is 162.4 g/mol) and the solution has a density of 1.2 g/mL.0.103 M0.212 M0.578 M0.635 M16.7 M

Answer 1

Answer: 0.635 M

Explanation:

Molarity : It is defined as the number of moles of solute present per liter of the solution.

Formula used :

$Molarity=\frac{n\times 1000}{V_s}$

where,

n= Moles=$\frac{\text{Given mass}}{\text{Molar mass}}=\frac{5.15g}{162.4g/mol}=0.0317moles$  

$V_s$ = volume of solution  = 150 ml

$Molarity=\frac{0.0317\times 1000}{150ml}=0.2114M$

$FeCl_3\rightarrow Fe^{3+}+3Cl^-$

as 1 mole of $FeCl_3$ gives 3 moles of $Cl^-$ ions

Thus molarity of $Cl^-$ = $3\times 0.2114=0.635M$

Molarity of $Cl^-$ = 0.635 M