liquid universal indicator colour observation with sodium P red rapid fizzing Q green slow fizzing R green no visible change The table shows tests carried o...
Question 1 Report
| liquid | universal indicator colour | observation with sodium |
|---|---|---|
| P | red | rapid fizzing |
| Q | green | slow fizzing |
| R | green | no visible change |
The table shows tests carried out on three colourless liquids found in an unlabeled laboratory box. One liquid is ethanol, one is ethanoic acid and one is water. The student adds universal indicator to separate samples, then adds a small piece of sodium to fresh samples. Gas from the sodium reaction is tested with a lighted splint.
| liquid | universal indicator colour | observation with sodium |
|---|---|---|
| P | red | rapid fizzing |
| Q | green | slow fizzing |
| R | green | no visible change |
(a) Name the liquid that is ethanoic acid. [1]
(b) State the gas made when sodium reacts with ethanol. [1]
(c) Give the identity of liquids Q and R. [2]
Answer Details
(a) Liquid P is ethanoic acid. [1] Red universal indicator shows that it is acidic, and acids react rapidly with sodium.
(b) Sodium reacting with ethanol produces hydrogen. [1]
(c) Liquid Q is ethanol [1] because it is neutral with universal indicator but reacts slowly with sodium. Liquid R is water [1] because it is neutral and gives no visible change in this test.
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