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प्रश्न
The chemical formula for rust is.............. .
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उत्तर
The chemical formula for rust is Fe2O3. x H2O
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संबंधित प्रश्न
Define ‘redox reaction’. Give one example.
Why does the colour of copper sulphate solution change when an iron nail is dipped in it?
Explain the following in term Oxidation of gain or loss of oxygen with two example.
Define corrosion.
The addition of oxygen to a substance is called ______ whereas removal of oxygen is called ______.
Give an example of an oxidation reaction.
When copper powder is heated strongly in air, it forms copper oxide. Write a balanced chemical equation for this reaction. Name
- substance oxidised, and
- substance reduced.
When a magnesium ribbon is heated, it burns in air to form magnesium oxide. Write a balanced chemical equation for this reaction. Name
- substance oxidised, and
- substance reduced.
In the reaction represented by the following equation:
\[\ce{CuO_{(s)} + H2_{(g)} -> Cu_{(s)} + H2O_{(l)}}\]
- name the substance oxidised
- name the substance reduced
- name the oxidising agent
- name the reducing agent
The process of respiration is ______.
You are given the following chemical equation:
\[\ce{Mg_{(s)} + CuO_{(s)} -> MgO_{(s)} + Cu_{(s)}}\]
This equation represents:
Fill in the blank
Oxidation is the removal of ......................and addition of ....................
Fill in the blank
In redox reaction oxidation and reduction occur ............................
Define an oxidation reaction.
TRUE \ FALSE
Hydrogen is a good oxidizing agent.
Identify from the following reaction the reactants that undergo oxidation and reduction.
\[\ce{2Ag2O → 4 Ag + O2 \uparrow}\]
Identify from the reaction the reactants that undergo oxidation and reduction.
2Mg + O2 → 2MgO
Compare hydrogen with alkali metals on the basis of:
Oxide formation
Give the general group study of hydrogen with reference to
reducing power
Why zinc and aluminium are considered to have a unique nature. Give balanced equations to support your answer.
State whether the following conversion is oxidation or reduction:
Cu2+ + 2 e-→ Cu
Divide the following reactions into oxidation and reduction half-reaction:
Zn + Cu2+ → Cu + Zn 2+
Divide the above equation into oxidation and reduction half-reactions.
A metal oxide that is reduced by hydrogen is
Name:
a substance that will reduce aqueous Iron(III)ions to iron(II)ions.
Name:
a gas that is oxidizing as well as a reducing agent.
Name:
a solid that is an oxidizing agent.
Complete and balance the following equation:
Zn +_________________→ZnCl2 + H2
Complete and balance the following equation:
CuO +__________→ Cu +___________
Complete and balance the following equation:
Fe + H2O →___________+____________
Explain the term reduction in term of addition and removal of oxygen/hydrogen with a suitable example.
Explain the following reaction with their balanced chemical equation.
Hydrogen sulphide reacts with sulphur dioxide.
Identify the following reactions as oxidation or reduction
- Na → Na+ + e
- Fe3+ + 2 e- → Fe+
Find the oxidation number of the elements in the following compounds.
- C in CO2
- Mn in MnSO4
- N in HNO3
Rusting of iron involves a chemical reaction which is a combination of:
Oxidation is a process which involves ____________.
\[\ce{MnO2 + 4HCl -> + 2H2O + Cl2}\]
Identify the substance oxidized in the above equation.
Select the oxidising agent for the following reaction:
\[\ce{H2S + I2 -> 2HI + S}\]
Identify the reducing agent in the following reactions
`2"H"_2 + "O"_2 -> 2"H"_2"O"`
Which among the following are physical or chemical change?
Sublimation of solid ammonium chloride
During the reaction of some metals with dilute hydrochloric acid, following observations are made.
Silver metal does not show any change
Explain this observation giving suitable reason.
On adding a drop of barium chloride solution to an aqueous solution of sodium sulphite, white precipitate is obtained :
- Write a balanced chemical equation for the reaction involved.
- What other name can be given to this precipitation reaction?
- On adding dilute hydrochloric acid to the reaction mixture, white precipitate disappears. Why?
Write a short note on oxidizing and reducing agents.
What is a redox reaction?
The formation of brown colour on the freshly unit surface of vegetables and fruits is because ______ of organic compounds present in them.
Oxidizing agents are otherwise called ______.
______ is a metal that has a high resistance to corrosion.
What are redox reactions? Give examples.
What is rancidity?
Find the oxidation number of the element in the following compound.
Zn in ZnSO4
Answer the questions based on the equation below:
\[\ce{CH3 - CH2 - OH ->[{[O]}][K2Cr2O7/H2SO4] CH3 - COOH}\]
- What type of reaction is it?
- What is the role of the chemical written on the arrow?
- Give one example of one such type of chemical as in answer (b).
It is recommended to use air tight containers for storing oil for a long time.
State the change in colour observed in following case mentioning the reason:
Copper powder is strongly heated in air.
Metals are good ______.
