Final answer:
To determine the molarity of the sodium hydroxide solution, calculate the moles of HCl that reacted, which also equals the moles of NaOH due to the 1:1 stoichiometry, and then divide by the volume of NaOH used. The molarity of NaOH is 0.14 M.
Step-by-step explanation:
To find the molarity of the sodium hydroxide (NaOH) solution used to titrate 35 mL of 0.1 M hydrochloric acid (HCl), we need to use the concept of molarity and the stoichiometry of the balanced chemical equation between HCl and NaOH, which is:
HCl + NaOH → NaCl + H₂O
First, calculate the number of moles of HCl:
Moles of HCl = volume (L) × molarity (M)
Moles of HCl = 0.035 L × 0.1 M = 0.0035 moles
Since the molar ratio between HCl and NaOH is 1:1, the moles of NaOH will also be 0.0035. Next, we calculate the molarity of NaOH using the volume of NaOH:
Molarity of NaOH = moles of NaOH / volume of NaOH (L)
Molarity of NaOH = 0.0035 moles / 0.025 L = 0.14 M
The molarity of the sodium hydroxide solution is therefore 0.14 M.