Question

Question #a407a

Answer 1

See below.

Explanation:

In this problem, we will use the concentration equation:

`M_1*V_1=M_2*V_2` where `M` is our molarity and `V` is our volume.

Step 1: Plug in the numbers given to us to the equation above.

`0.171*86.9=M_2*25.0`

The left side of this equation is the data for the base and the right side is the data for the acid.

Step 2: Solve algebraically for `M_2`.

`14.9=M_2*25.0`

(Divide by 25.0 on both sides):

`0.594=M_2`

This is our concentration of the `HCl` concentration.

NOTE: This equation was used because the balanced chemical reaction has a mole ratio of 1:1 between the acid and base.

(`1NaOH+1HCl->NaCl+H_2O`)

IF: This reaction had a mole ratio of 2:1 between the acid and base (i.e. `2NaOH+1H_2SO_4->Na_2SO_4+2H_2O`) our conentration equation would change to:

`M_1*V_1=2(M_2*V_2)`

Where the left side is again the base and the right side is the acid.

I hope this helps!