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प्रश्न
Write chemical formula for rust.
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उत्तर
Chemical formula for rust: Fe2O3•xH2O
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संबंधित प्रश्न
Define ‘redox reaction’. Give one example.
What is an oxidising agent?
Write the chemical formula of rust.
When a magnesium ribbon burns in air with a dazzling flame and forms a white ash, is magnesium oxidised or reduced? Why?
In the reaction represented by the equation:
\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2}\]
- name the substance oxidised.
- name the oxidising agent.
- name the substance reduced.
- name the reducing agent.
Give one example of an oxidation-reduction reaction which is also a displacement reaction.
Explain the following in terms of gain or loss of oxygen with one example:
Oxidation
Fill in the blank
In redox reaction oxidation and reduction occur ............................
Indicate which of the following statement is true and which is false:
The removal of hydrogen from a substance is called reduction.
Define an oxidation reaction.
MULTIPLE CHOICE QUESTIONS
The process of adding oxygen to a substance is called
- oxidation.
- reduction.
- displacement.
- hydrogenation.
How would you change a metal like Cu into its ions?
Identify from the reaction the reactants that undergo oxidation and reduction.
2Mg + O2 → 2MgO
Explain the following in term of gain or loss of oxygen with two examples.
Oxidation
Compare hydrogen with alkali metals on the basis of:
Oxide formation
Give the general group study of hydrogen with reference to
burning
Why zinc and aluminium are considered to have a unique nature. Give balanced equations to support your answer.
Describe briefly the ionic concept of oxidation and reduction. Give an equation to illustrate.
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
Mg + 2HCl → MgCl2 + H2
Divide the following reactions into oxidation and reduction half-reaction:
Cl2 + 2Br- → Br2 + 2Cl-
Divide the above equation into oxidation and reduction half-reactions.
A metal oxide that is reduced by hydrogen is
Which of the following statements about hydrogen is incorrect?
For the reaction PbO + H2→ Pb + H2O, which of the following statements is wrong?
Choose terms from the options given in brackets to complete this sentence.
When CuO reacts with hydrogen,………………… is reduced and ……………….is oxidized to ………………….
(CuO, H2, Cu, H2O)
Name:
an oxidizing agent that does not contain oxygen.
Name:
a solid that is an oxidizing agent.
State what is oxidising agent. Give an example of oxidising agent in the gaseous, liquid, and solid form.
Which of the following statements about the given reaction are correct?
\[\ce{3Fe_{(s)} + 4H2O_{(g)} -> Fe3O4_{(s)} + 4H2_{(g)}}\]
(i) Iron metal is getting oxidised.
(ii) Water is getting reduced.
(iii) Water is acting as the reducing agent.
(iv) Water is acting as oxidising agent.
Select the oxidising agent for the following reaction:
\[\ce{H2S + I2 -> 2HI + S}\]
Identify the reducing agent in the following reactions
`4"NH"_3 + 5"O"_2 -> 4"NO" + 6"H"_2"O"`
Identify the oxidising agent (oxidant) in the following reactions
`"Pb"_3"O"_4 + 8"HCl" -> 3"PbCl"_2 + "Cl"_2 + 4"H"_2"O"`
Which among the following are physical or chemical change?
Curding of milk
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.
The reaction of sodium metal is found to be highly explosive
Explain this observation giving suitable reason.
Why do we store silver chloride in a dark coloured bottle?
What happens when zinc granules are treated with dilute solution of H2SO4, HCl, HNO3, NaCl and NaOH Also write the chemical equations if reaction oçcurs.
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?
You are provided with two containers made up of copper and aluminium. You are also provided with solutions of dilute HCl, dilute HNO3, ZnCl2 and water. In which of the above containers, can these solutions be kept?
Mention some oxidation reactions that occur in daily life.
The formation of brown colour on the freshly unit surface of vegetables and fruits is because ______ of organic compounds present in them.
The tarnishing of metals is due to the formation of ______.
Choose the odd one out and write the reason:
Choose the odd one out and write the reason:
Identify the following reactions as oxidation/reduction/redox reaction
Zn + CuSO4 → Cu + ZnSO4
What are reducing agents? Give examples.
Find the oxidation number of the element in the following compound.
Ca in CaH2
Find the oxidation number of the element in the following compound.
A1 in AlCl3
State the change in colour observed in following case mentioning the reason:
Copper powder is strongly heated in air.
The oxidizing agent in the equation \[\ce{S + 2H2SO4 -> 3SO2 + 2H2O}\] is ______.
