Moles HCl reacted : 0.0135
Molarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution
[tex]\large {\boxed {\bold {M ~ = ~ \dfrac {n} {V}}}[/tex]
Where
M = Molarity
n = Number of moles of solute
V = Volume of solution
So to find the number of moles can be expressed as
n = V x M
The volume of HCl 30 cm³=3.10⁻² dm³
Molarity of HCl = 0.45 mol/dm³
so moles HCl reacted :
[tex]\tt n=3.10^{-2}\times 0.45=0.0135[/tex]