Zinc is commonly extracted from an ore containing zinc sulfide, ZnS\text{ZnS}ZnS.
Extracting zinc from the zinc sulfide ore involves two steps.
Step 1: The zinc sulfide ore is roasted in oxygen to produce zinc oxide, ZnO\text{ZnO}ZnO, and sulfur dioxide, SO2\text{SO}_2SO2.
Step 2: The zinc oxide is heated with carbon to produce zinc and carbon monoxide.
The reaction in step 1 is an exothermic reaction.
Draw a labelled reaction profile diagram for an exothermic reaction on the axes provided below.
Label the activation energy and the energy change on your diagram.
In step 2, the zinc oxide is reduced by carbon.
ZnO+C→Zn+CO\text{ZnO} + \text{C} \rightarrow \text{Zn} + \text{CO}ZnO+C→Zn+CO
Explain, in terms of electron transfer, why carbon is called a reducing agent in this reaction.
Solid silver reacts with dilute nitric acid, HNO3\text{HNO}_3HNO3.
Silver nitrate, AgNO3\text{AgNO}_3AgNO3, nitrogen monoxide, NO\text{NO}NO, and water are made.
Write a balanced symbol equation for this reaction.
How many moles of silver nitrate would be produced if 32.4 g32.4\text{ g}32.4 g of silver reacts with excess nitric acid?
Give your answer to 2 significant figures (assume the relative atomic mass of silver, Ar(Ag)=108A_r(\text{Ag}) = 108Ar(Ag)=108).