Q2 Different metals were discovered at different times throughout history. In general, more reactive metals were discovered much more recently than less reactive metals.
Very unreactive metals, such as gold, were discovered in ancient times.
a) Suggest an explanation for the link between a metal's date of discovery
and its reactivity.

The first metal known to be prepared from its ore was copper, perhaps as early as 6000BC6000BC in the Middle East. The ore, which contained copper(II) oxide, was heated with charcoal, which was prepared by the incomplete burning of wood, and is mainly elemental carbon. Later, iron and tin were prepared in the same way. Bronze, an alloy of copper and tin, was made by mixing copper-containing ore with tin ore and heating the mixture in the presence of charcoal. 

answer: the value of enthalpy change will be -152.80 kj.

solution:

pressure = 1atm , temperature = = 298 k

given that pressure and temperature are same in both gases , the number of moles of both gases can be determined by the ideal gas equation.

according to reaction 3 moles no are reacting with 1 mol of ,then 0.49 mol of no will react with moles of ozone that is 0.16 moles of ozone. since, no is limiting reagent and is an excessive reagent.

enthalpy change for the reaction between the given volumes of the gases is :