Core Practicals In Paper 1 Flashcards
Explain the simple distillation of ink
Ink is in a flask with a bung, thermometer and delivery tube going into a beaker of ice so the vapour can be condensed. Gently heat the ink with a Bunsen burner until you collect a few cm cubed of distillate. Record maximum temp obtained
Explain the chromatography of ink
Draw a pencil line near the bottom of the paper and add a small spot of ink. Add water to the beaker but not above the line. Allow some time for the water to rise. Mark the line where the solvent reached and allow to dry. Measure distance travelled by solvent and ink from the line and figure out the Rf value.
Explain the preparing copper sulphate experiment
Measure 20cm cubed of sulphuric acid and pour into a conical flask. Warm in a water bath to 50 degrees, and add a little copper oxide powder and stir. Keep adding powder till it no longer reacts and is in excess. Filter mixture then transfer filtrate to an evaporating basin. Heat till crystals start to form then leave to naturally evaporate.
Explain the investigating neutralisation experiment
Measure 50cm cubed of dilute hydrochloric acid and estimate and record the pH. Place a piece of universal indicator paper on a white tile, place the end of a glass rod into the acid and dot it onto the paper. Colour match the colour and record it’s pH. Measure 0.3g of calcium hydroxide powder in a weighing boat. Add it to the acid and estimate pH. Repeat previous steps seven times so you end up adding 2.4g of powder. Plot a graph with pH on the y axis and mass of powder on the x.
Explain the electrolysis of a copper sulphate solution
Measure the weights of the two clean copper electrodes. Set up electrolysis, turn power on and turn variable resistor to give a current of 0.2A and leave the power on for 20 minutes.
Turn power off, wash electrodes with distilled water and dip in propanone. Lift off, shake off propanone and leave to evaporate the rest. Measure and record weights of dry electrodes. Repeat using currents of 0.3,0.4, 0.5A.
Explain the electrolysis of copper sulphate using graphite electrodes
Set up electrolysis using graphite as electrodes and record what you see.
Explain the acid-alkali titration
Rinse a burette with hydrochloric acid, then fill the burette with the acid. Record the initial volume of the burette. Rinse a pipette with sodium hydroxide then fill to the 25cm cubed. Empty into a conical flask. Add a few drops of methyl orange indicator and place on a white tile. Add acid whilst swirling the flask, and when the indicator starts changing colour rinse the sides of the flask with distilled water to ensure all acid is being involved. Add acid drip by drop until the solution turns colourless. Write down final volume in the burette. Repeat until concordant results are obtained.
