Testing for acids and bases - 4th class

4th class investigated acids and bases. First we examined the pH scale, and saw where common household items appeared on it. We made indicator by steeping red cabbage in hot water for an hour. We ensured fair testing by using exactly 5ml of indicator and 5ml of substance under test in each case. We found that lemon juice was the most acidic item we tested, with bicarbonate of soda being the most alkaline. We found that tea and coffee are both acidic, but that reading the indicator colour level was hard because both tea and coffee are brown.