Question

What volume of 1.5 M HCl solution do you need to use to make 500 mL of 0.25 M HCl solution by dilution?

Answer 1

83 mL

Explanation:

In order to solve this dilution, we must use the dilution equation, which states that `M_1V_1 = M_2V_2`. M stands for the molarity of a solution, while V stands for the volume of a solution. The subscript 1 stands for the initial conditions of a solution, while the subscript 2 stands for the final condition of the solution. Using the given data, we can see that `(1.5 M)(V_1)=(0.25 M)(500 mL)`. Solving for `V_1` gives us approximately 83 mL of 1.5 M HCl solution.

Answer 2

I get `83 \ "mL"`.

Explanation:

Let's use the concentration equation, which states that

`m_1V_1=m_2V_2`

So, we got:

`1.5 \ "M"*V_1=0.25 \ "M"*0.5 \ "L"`

`V_1=(0.25color(red)cancelcolor(black)"M"*0.5 \ "L")/(1.5color(red)cancelcolor(black)"M")`

`=0.083 \ "L"`

`~~83 \ "mL"`