Temperature Changes & Titrations
Temperature change experiments measure how much heat reactions produce or absorb. You'll mix hydrochloric acid with different volumes of sodium hydroxide in a polystyrene cup (which prevents heat loss) and record the maximum temperature each time.
Start with 30cm³ of acid, then gradually add 5cm³ portions of alkali whilst stirring with your thermometer. The temperature will rise to a peak, then start dropping - that peak shows you the neutralisation point.
Titrations help you find unknown concentrations by carefully adding acid to alkali until neutralisation occurs. You'll use phenolphthalein indicator, which changes from pink to colourless when the solution becomes neutral. The key is adding acid drop by drop near the end point.
Read your burette at eye level using the bottom of the meniscus (the curved bit). You need concordant results within 0.1cm³ of each other, so expect to repeat this several times until your readings are consistent enough for accurate calculations.
Remember: Always place your conical flask on a white tile - it makes colour changes much easier to spot during titrations.