Question

Pre-Lab Questions 1. Define each of the following terms: a. Oxidation: EXPERIMENT 5 b. Reduction: c. Redox reaction: d. Activity: 2. In the following reaction identify the substance that is oxidized and the substance that is reduced. Which metal is more active? 2Al(s) + 3Cu(aq) + 2Al(aq) + 3Cu(s) Oxidized Reduced = More active = 3. Why is it necessary to clean the surfaces of the metal samples before testing them in the metal ion solutions? 4. You will not be testing the activity of sodium (Na) or potassium (K) in this lab. Based on the periodic trends for activity, would you expect these metals to be more active or less active than the metals studied in this lab? Explain. EXPERIMENT 5: REDOX CHEMISTRY-ACTIVITY OF METALS

Answer 1

1.a. Oxidation- This term can be explained in various way.

In earlier Chemistry, Oxidation was defined as gaining of oxygen or losing of hydrogen with respect to the oxygen included term and hydrogen related term. But the commonly used defition is

the species which loss electron with respect to the other species present in the reaction is to be called that oxidation occurs and the species is oxidised.

For e. g.

Na(s)-> Na(+) +e

1.b.Reduction - The reduction is nothing bout opposite of oxidation. i. e. losing of oxygen or gaining of hydrogen or gaining of electron is called reduction.

e. g. Na(+) +e-> Na

1.c. Redox reaction- this term contaion 'Red' and 'Ox'. i. e. the proces in which reduction and oxidation reaction occurs simultaneously is called Redox reaction.

1.d. Activity - this is the measure of effective concentration under non ideal condition of a subjected species. This is denoted by a.rather,in redox this term is defined as the more negative reduction potential have rhe more reactive the species is.

2.Oxidised= Al

Reduced = Cu(2+)

More active= Al

3.Some metals are so reactive to air that they make an oxidsed fime on their surface. So it is necessary to clean the surface of the metal surface to proceed the reaction in expected way.

4. Obviously the metals are studied in lab are less reactive. Because this metals are too reactive as they make explosion with air if they used as raw metal. that is why in lab this metals are made available in form of some stable compound as NaCl...KCl..etc.