Final answer:
The number of moles of HCl used to neutralize the KOH solution is calculated by multiplying the concentration of HCl (2 mol/dm³) by the volume in dm³ (0.035 dm³), resulting in 0.07 moles of HCl.
Step-by-step explanation:
To determine the number of moles of hydrochloric acid used to neutralize the potassium hydroxide solution, we use the equation:
Moles = Concentration × Volume
Where concentration is given in moles per cubic decimeter (mol/dm³), and volume is given in cubic decimeters (dm³). First, we need to convert the volume from cm³ to dm³:
35 cm³ = 35 / 1000 dm³ = 0.035 dm³
Now, applying the formula:
Moles = 2 mol/dm³ × 0.035 dm³
Moles = 0.07 mol
So there were 0.07 moles of HCl in the 35 cm³ volume used to titrate the KOH solution.