Copper is commonly extracted from an ore containing copper(I) sulfide, Cu2S\text{Cu}_2\text{S}Cu2S.
Extracting copper from the copper(I) sulfide ore involves two steps.
Step 1: The copper(I) sulfide ore is roasted in air to produce copper(I) oxide, Cu2O\text{Cu}_2\text{O}Cu2O.
Step 2: The copper(I) oxide is heated with carbon.
The reaction in step 1 is an exothermic reaction.
Draw a labelled reaction profile diagram for an exothermic reaction.
Label the activation energy and the energy change on your diagram.
In step 2, the copper(I) oxide is reduced by carbon.
Cu2O+C→2Cu+CO\text{Cu}_2\text{O} + \text{C} \rightarrow 2\text{Cu} + \text{CO}Cu2O+C→2Cu+CO
Explain, in terms of electron transfer, why carbon is called a reducing agent in this reaction.
Solid copper reacts with dilute nitric acid, HNO3\text{HNO}_3HNO3.
Copper(II) nitrate, Cu(NO3)2\text{Cu}(\text{NO}_3)_2Cu(NO3)2, nitrogen monoxide, NO\text{NO}NO, and water are made.
Write a balanced symbol equation for this reaction.
How many moles of copper(II) nitrate would be produced if 12.7 g12.7\text{ g}12.7 g of copper reacts with excess nitric acid?
Give your answer to 2 significant figures (assume the relative atomic mass of copper, Ar(Cu)=63.5A_r(\text{Cu}) = 63.5Ar(Cu)=63.5).
Energetics Questions
Practise OCR GCSE Chemistry Energetics with exam-style questions for Foundation and Higher tier. 30 questions, matched to the OCR GCSE Chemistry (J248) specification and written in Paper 1 and Paper 2 (Foundation Tier) or Paper 3 and Paper 4 (Higher Tier) style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.