Question

the titration of 11.00 ml of hcl solution of unknown concentration requires 12.17 ml of a 0.150 m naoh solution to reach the equivalence point. what is the concentration of the unknown hcl solution in m? express your answer in moles per liter to three significant figures. m(hcl) = m

Explanation:

Step1: Write the balanced chemical equation

$HCl + NaOH
ightarrow NaCl + H_2O$
The mole - ratio of $HCl$ to $NaOH$ is $1:1$, so $n_{HCl}=n_{NaOH}$ at the equivalence point.

Step2: Use the formula $n = M\times V$

We know that $M_{NaOH}=0.150\ M$, $V_{NaOH}=12.17\ mL = 0.01217\ L$, and $V_{HCl}=11.00\ mL=0.01100\ L$.
Since $n_{HCl}=n_{NaOH}$, and $n = M\times V$, we have $M_{HCl}\times V_{HCl}=M_{NaOH}\times V_{NaOH}$.

Step3: Solve for $M_{HCl}$

$M_{HCl}=\frac{M_{NaOH}\times V_{NaOH}}{V_{HCl}}$
Substitute the values: $M_{HCl}=\frac{0.150\ mol/L\times0.01217\ L}{0.01100\ L}$
$M_{HCl}=\frac{0.150\times0.01217}{0.01100}\ mol/L$
$M_{HCl}= 0.166\ mol/L$

Answer:

$0.166$