100 likes | 221 Vues
Acids and Bases. And Neutralisation Reactions p. 80-82. What are acids?. Working together with your bench group & using the information in your text book (Ch 4 p 80), expand this Mind Map. Acids. eg. Have a sour taste. Are used for. What are bases?.
E N D
Acids and Bases And Neutralisation Reactions p. 80-82
What are acids? Working together with your bench group & using the information in your text book (Ch 4 p 80), expand this Mind Map Acids eg Have a sour taste Are used for
What are bases? • Working together with your bench group, expand this Mind Map bases eg Have a bitter taste (think of baking soda!) Are used for
Experiment 13: Testing for Acids and Bases Aims: • to determine which substances are acids and bases using universal indicator • to compare the colour produced using plant indicators with those produced using universal indicator
Materials • Glass plate with wells • Droppers • Universal indicator • Colour chart • Red Cabbage Indicator • Hydrochloric acid (HCl) • Sodium Hydroxide (NaOH) • Vinegar • Lemon Juice • Sodium bicarbonate (NaHCO3) • Water (from tap) • Other Substances as supplied
Method • Collect the substances listed above and place about 0.5 ml in separate wells on the glass plate, as shown. • Use a new well for each substance. • Add two drops of Universal indicator to each well • Record the colour that the indicator became • Use the glass test plate outline supplied to estimate the pH and record this also. • Test these substances with Red Cabbage Indicator and record the colours on a new sheet • Hydrochloric acid (HCl) • Sodium Hydroxide (NaOH) • Vinegar • Lemon Juice • Sodium bicarbonate (NaHCO3) • Water (from tap) • Copy the table on the next slide into your workbook • Safety Issues?
Neutralisation Reactions • Acids and bases react together! (Remember the vinegar and Bicarb?) • The general overall word equation is Acid + Base a Salt + water Except if you use a bicarbonate or carbonate (which are bases) and then it’s Acid + bicarbonate/carbonate a Salt + water + carbon dioxide
Try This! • Put a small amount of vinegar + 2 drops only of indicator in a test tube • Add 0.1 M NaOH drop by drop • Can you get the pH to be just 7?
Activities • On the Intranet in the Acids and Bases Section try • GEMS Alien Juice Bar • Treasure Puzzle