Question

Write the balanced equation occurring between HCl(aq) and NaOH(aq). a. It takes 15 mL of 0.125 M NaOH to reach the end point of the reaction. How many moles of NaOH have you added? b. What is the mole ratio between HCl and NaOH? How many moles of HCI were in the titrated sample? c. At the beginning of the titration, there were 22 mL of HCl. What was the original concentration of HCl?

Answer 1

a)

Mol of NaOH = M(NaOH)*V(NaOH)

= 0.125 M * 15 mL

= 0.125 M * 0.015 L

= 1.9*10^-3 mol

Answer: 1.9*10^-3 mol

b)

The reaction is:

HCl + NaOH -> NaCl + H2O

The ration of HCl to NaOH is 1:1

So,

Mol of HCl = mol of NaOH

= 1.9*10^-3 mol

Answer: 1:1, 1.9*10^-3 mol

c)

Mol of HCl = M(HCl)*V(HCl)

1.9*10^-3 mol = M * 22 mL

1.9*10^-3 mol = M * 0.022 L

M = 0.086 M

Answer: 0.086 M