Question

A student titrates 25.00 cm³ of hydrochloric acid with 28.60 cm³ sodium hydroxide solution of concentration 0.200 moles per dm³. The equation for the reaction is: HCl + NaOH to NaCl + H₂O. Calculate the concentration of the hydrochloric acid.

Answer 1

To calculate the concentration of the hydrochloric acid, use the equation HCl + NaOH → NaCl + H₂O and the given information. First, find the moles of sodium hydroxide (NaOH) used. Then, since the reaction is a 1:1 ratio between HCl and NaOH, the moles of HCl is also found. Finally, calculate the concentration of the hydrochloric acid.

Step-by-step explanation:

To calculate the concentration of the hydrochloric acid, we can use the equation HCl + NaOH → NaCl + H₂O and the information provided. First, let's find the number of moles of sodium hydroxide (NaOH) used:

moles of NaOH = concentration of NaOH × volume of NaOH

moles of NaOH = 0.200 mol/dm³ × 0.02860 dm³

moles of NaOH = 0.00572 mol

Since the reaction is a 1:1 ratio between HCl and NaOH, the number of moles of hydrochloric acid (HCl) is also 0.00572 mol. Now we can find the concentration (c) of the hydrochloric acid:

c = moles/volume (in dm³)

c = 0.00572 mol/0.02500 dm³

c = 0.2288 mol/dm³

Therefore, the concentration of the hydrochloric acid is 0.2288 mol/dm³.