Question

If it requires 35.0 milliliters of 0.50 molar NaOH to neutralize 25.0 milliliters of HCl, what is the concentration of the HCl solution? (3 points)

Balanced equation: NaOH + HCl yields NaCl + H2O


0.36 M HCl

0.70 M HCl

1.1 M HCl

1.4 M HCl

Answer 1

0.7M

Step-by-step explanation:

Volume of NaOH = 35mL = 0.035L

Concentration of NaOH = 0.5M

Volume of HCl = 25mL = 0.025L

Concentration of HCl = ?

Solution;

The balanced equation of the reaction is shown below:

NaOH + HCl → NaCl + H₂O

To solve this problem, we solve from the known to the unknow. The known here is the parameters of NaOH. From here, we can find the number of moles;

Number of moles of NaOH = concentration x volume= 0.035 x 0.5

= 0.0175mole

From the balanced reaction equation, we can state that:

1 mole of NaOH reacted with 1 mole of HCl

0.0175mole of NaOH will reacted with 0.0175mole of HCl

Now that we know the number of moles of the acid used, we can calculate the concentration of the acid used using the expression below:

Concentration of acid =
`(number of moles of acid)/(volume of acid)`

Concentration of acid=
`(0.0175)/(0.025)` = 0.7M