Чарикова Ирина Викторовна, учитель биологии и химии
Every citrus fruit contains organic acids, such as citric acid and ascorbic acid, also known as vitamin C. Yet limes or lemons taste quite acidic while oranges or mandarins are on the sweet side. Which among citrus fruits is the "world champion" in acidity? Is there a correlation between acid taste and pH-levels? Are there variations in pH for the same citrus fruit grown in various countries, regions or climate zones. Those questions will be explored in this activity.
What happens to unfinished soda? Many soft drinks are easy to tell apart by their tastes; they all are made from different recipes. But what they have in common is the presence of carbon dioxide. Compare the original acidity of soda with what happens to pH levels as the soda loses its carbonation and goes “flat”.