Answer:
0.38dm³ or 38mL
Explanation:
Given parameters:
molarity of HCl = 5.5M
volume of Mg(OH)₂ = 85mL
molarity of Mg(OH)₂ = 1.22M
Unknown:
Volume of HCl solution = ?
Solution:
we have to adopt the mole concept to solve this problem.
Complete reaction equation:
2HCl + Mg(OH)₂ → MgCl₂ + 2H₂O
For a standard acid titrated against a standard base,
aA + bB → cC + dD
[tex]\frac{number of moles of A}{number of moles of B} = \frac{a}{b}[/tex]
A is the acid, B is the base
since number of moles = C x V
C is the molarity
V is the volume
CₐVₐ / CₓVₓ = a / x
a = acid
x = base
85mL to dm³ = 0.085dm³
since the unknown is Vₐ,
let us make it the subject of the expression;
Vₐ = (a/x) x ( CₓVₓ/ Cₐ)
Va = [tex]\frac{2}{1} x \frac{1.22 x 0.085}{5.5}[/tex] = 0.38dm³
