Air & water


Complete the crossword, then click on "Check" to check your answer. If you are stuck, you can click on "Hint" to get a free letter. Click on a number in the grid to see the clue or clues for that number.

          2          3     
4     5                    
 15    16                    
 18        19                


2. bases dissolved in water are called -------
6. goes cloudy when carbon dioxide enters
7. 78% of air
8. preparing a sample of NaCl by reacting HCl against NaOH
9. acid reacts with base to form water and ----
10. the de-composition of water using an electric current
12. reaction between acid and base
13. oxygen supports it, carbon dioxide doesn't
14. one chemical used to show the presence of another chemical
17. manganese dioxide acts as this - speeds of release of oxygen
18. burn carbon in oxygen, the product turns moist litmus this colour
20. most air cantins a small amount of water ------
21. the liquid used to produce oxygen is hydrogen --------


1. the presence of certain dissolved salts in water is called --------
3. 21% of air
4. removal of hardness in water can be done with this
5. technique used to obtain a sample of water from sea-water
11. carbon dioxide gas is released by hydrochloric acid dropped onto calcium ---------
15. the gas that composes two-thirds of water
16. a tiny bit of this might speed up10 across!!
19. air is a mixture of these