(a) Explain the following in terms of gain or loss of oxygen with one example each:(i) oxidation (ii) reduction(b) When copper powder is heated strongly in air, it forms copper oxide. Write a balanced chemical equation for this reaction. Name (i) substance oxidised, and ii) substance reduced.
(a) $ZnO\ +\ C\ \xrightarrow{\ Heat} \ Zn\ +\ CO$
(i) In the above reaction, Oxygen is added to Carbon. By definition, the addition of oxygen to a substance is called oxidation, so we can say that Carbon is oxidised to Carbon dioxide.
(ii) On the other hand, Oxygen is removed from Zinc oxide. By definition, the removal of oxygen from a compound is called reduction, so, we can say that Zinc oxide is reduced to Zinc.
(b) When copper powder is heated strongly in air, it forms copper oxide.
$2Cu\ +\ O_{2} \ \rightarrow 2CuO$
(i) Copper is oxidised. (ii) Oxygen is reduced.
Related Articles
- (a) Define the following in terms of gain or loss of hydrogen with one example each:(i) oxidation (ii) reduction(b) When a magnesium ribbon is heated, it burns in air to form magnesium oxide. Write a balanced chemical equation for this reaction. Name (i) substance oxidised, and (ii) substance reduced.
- Explain the following in terms of gain or loss of oxygen with two examples each:(a) Oxidation and(b) Reduction
- What is an oxidation reaction? Identify in the following reaction (i) the substance oxidised, (ii) the substance reduced:ZnO + C ----> Zn + CO
- (a) What is a redox reaction? Explain with example.(b) When a magnesium ribbon burns in air with a dazzling flame and forms a white ash, is magnesium oxidised or reduced? Why?(c) In the reaction represented by the equation:MnO2 + 4HCl ----> MnCl2 + 2H2O + Cl2 (i) name the substance oxidised. (ii) name the oxidising agent.(iii) name the substance reduced. (iv) name the reducing agent.
- (i) Given below are the steps for extraction of copper from its ore. Write the reaction involved.(a) Roasting of copper(I)sulphide(b) Reduction of copper(I)oxide with copper(I)sulphide.(c) Electrolytic refining.(ii) Draw a neat and well-labelled diagram for electrolytic refining of copper.
- What happens when (Write the balanced equation involved) –(i) Copper is heated in air?(ii) Aluminium oxide is reacted with hydrochloric acid?(iii) Potassium reacts with water?(iv) Cinnabar is heated in air?(v) Aluminium oxide reacts with sodium hydroxide?
- A solution of a substance ‘X’ is used for white washing.(i) Name the substance ‘X’ and write its formula.(ii) Write the reaction of the substance ‘X’ named in (i) above with water.
- Mention with reason the colour changes observed when :(i) silver chloride is exposed to sunlight.(ii) copper powder is strongly heated in the presence of oxygen.(iii) a piece of zinc is dropped in copper sulphate solution.
- When a green iron salt is heated strongly, its colour finally changes to black and odour of burning sulphur is given out(i) Name the iron salt X.(ii) Name the type of reaction.(iii) Write the balanced chemical equation for the reaction involved.(iv) Is this reaction exothermic or endothermic?(v) Give one more example of this type of reaction.
- You might have noted that when copper powder is heated in a china dish, the reddish brown surface of copper powder becomes coated with a black substance.(a) Why has this black substance formed?(b) What is this black substance?(c) Write the chemical equation of the reaction that takes place.(d) How can the black coating on the surface be turned reddish brown?
- When hydrogen is passed over copper oxide, copper and steam are formed. Write a balanced equation for this reaction and state which of the chemicals are:(i) elements (ii) compounds (iii) reactants (iv) products (v) metals (vi) non-metals
- Zinc oxide reacts with carbon, on heating, to form zinc metal and carbon monoxide. Write a balanced chemical equation for this reaction. Name (i) oxidising agent, and (ii) reducing agent, in this reaction.
- (a) What is a homologous series? Explain with an example.(b) Define the following terms giving one example of each.(i) Esterification(ii) Addition reaction
- Write balanced chemical equations to explain what happens, when(i) Mercuric oxide is heated.(ii) Mixture of cuprous oxide and cuprous sulphide is heated.(iii) Aluminium is reacted with manganese dioxide.(iv) Ferric oxide is reduced with aluminium.(v) Zinc carbonate undergoes calcination.
- On heating blue coloured powder of copper (II) nitrate in a boiling tube, black copper oxide, O2 and a brown gas X is formed.(a) Identify the type of reaction and gas X.(b) Write the balanced chemical equation of the reaction.(c) Write the pH range of the aqueous solution of the gas X.
Kickstart Your Career
Get certified by completing the course
Get Started
Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies