Answer : 399.8 ml of [tex]Ba(OH)_2[/tex] solution must be diluted with water.
Solution : Given,
Mass of [tex]Ba(OH)_2[/tex] = 72.84 g
Volume of solution = 1.7 L
Molarity of water = 0.1 mole/L
Volume of water = 1 L
First we have to calculate the molarity of [tex]Ba(OH)_2[/tex] solution.
Formula used : [tex]M=\frac{w_b}{M_b\times V_s}[/tex]
where,
M = molarity of [tex]Ba(OH)_2[/tex] solution
[tex]w_b[/tex] = mass of [tex]Ba(OH)_2[/tex]
[tex]M_b[/tex] = molar mass of [tex]Ba(OH)_2[/tex]
[tex]V_s[/tex] = volume of solution
Now put all the given values in this formula, we get
[tex]M=\frac{72.84g}{(171.34g/mole)\times (1.7L)}[/tex]
[tex]M=0.25007mole/L[/tex]
Now we have to calculate the volume of [tex]Ba(OH)_2[/tex] solution.
Formula used : [tex]M_1V_1=M_2V_2[/tex]
where,
[tex]M_1[/tex] = molarity of [tex]Ba(OH)_2[/tex] solution
[tex]M_2[/tex] = molarity of water
[tex]V_1[/tex] = volume of [tex]Ba(OH)_2[/tex] solution
[tex]V_2[/tex] = volume of water
Now put all the given values in this formula, we get
[tex](0.25007mole/L)V_1=(0.1mole/L)\times (1L)[/tex]
By rearranging the term, we get
[tex]V_1=0.3998L=399.8ml[/tex] (1 L = 1000 ml)
Therefore, 399.8 ml of [tex]Ba(OH)_2[/tex] solution must be diluted with water.