Answers section
Questions 6.5
- What does the part, 2H2O, indicate to us about the salt?
- How many salts are represented in this formula?
- From your knowledge of effect of heat on salts, describe the expected change when trona is heated till no further change occurs.
- Name the final product left.
Answers to Questions 6.5
- It is a hydrated salt. 2H2O shows that the salt combines with two molecules of water of crystallization.
- There are two salts in trona.
- A colourless vapour that readily condenses on cooler parts and turns anhydrous copper (II) sulphate blue, and a gas that forms white precipitate with calcium hydroxide solution. A white solid is left, which does not change further.
- The residue (final solid) is sodium carbonate.