Question

30 mL of 0.100 M HCL and 10.0 mL of 0.470 M HCLH+Cl-

Answer 1

Let us first define what the molarity of a substance corresponds to. This is defined as the moles of solute (n) per liter of solution (V), so we will have the following equation:

$M=\frac{n_T}{V_T}$

Where,

nT is the total number of moles

VT is the total volume in liters

M is the molarity of the solution

When we have a mixture we must add the total moles and the total volume as follows:

$M=\frac{n_A+n_B}{V_A+V_B}$

Now, the moles of each solution can be found by clearing the moles of the first equation.

But first, we have two solutions, we will call them solution a and solution b, the conditions are.

Solution a

Va=30mL=0.030L

Ma=0.100M

Solution b

Vb=10.0mL = 0.0100L

Mb=0.470M

Now for each solution, we have the following equation to find the number of moles:

$\begin{gathered} n_A=M_A\times V_A \\ n_B=M_B\times V_B \end{gathered}$

If we replace this equation into the second equation we will have:

$M=\frac{M_AV_A+M_BV_B}{V_A+V_B}$

We replace the known data:

$\begin{gathered} M=\frac{0.100M\times0.030L+0.470M\times0.010L}{0.030L+0.010L} \\ M=0.19M \end{gathered}$

Since both ions are in the same concentration, that is to one ion per molecule, the concentration will be the same.

H+ = 0.19M

Cl- =0.19M