SECONDARY FOUR SCIENCE(CHEMISTRY) EXERCISE 3 1. Liquid sodium reacts with hydrogen gas to give an ionic solid, sodium hydride (NaH). (a) By using oxidation numbers, explain why this is a redox reaction. (b) Draw a dot and cross diagram to show the electronic structure of sodium hydride. You only need to show the valence electrons. (c) Explain why sodium hydride conducts electricity when dissolved in aqueous solution. 2. Argon is often used in light bulbs. (a) Give one property of argon that makes it suitable for this application. (b) How many valence electrons does one atom of argon have? 3. Zinc can be obtained from different ore forms. The extraction of zinc typically involves two processes. The first process involves the decomposition of zinc carbonate. The second process involves the reduction of the zinc oxide with charcoal (a form of carbon). (a) Write two bal...
Posts
Showing posts with the label *Challenging O level chemistry questions