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प्रश्न
When the positive charge on an ion increases or the negative charge on them decreases it is called as _______.
पर्याय
reduction
corrosion
oxidation
decomposition
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उत्तर
When the positive charge on an ion increases or the negative charge on them decreases it is called as oxidation.
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संबंधित प्रश्न
What is an oxidising agent?
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.
Write the chemical formula of rust.
Identify in the following reaction (a) the substance oxidised, and (b) the substance reduced:
\[\ce{ZnO + C -> Zn + CO}\]
In the following reaction between lead sulphide and hydrogen peroxide:
\[\ce{PbS_{(s)} + 4H2O2_{(aq)} -> PbSO4_{(s)} + 4H2O_{(l)}}\]
- Which substance is reduced?
- Which substance is oxidised?
When a magnesium ribbon burns in air with a dazzling flame and forms a white ash, is magnesium oxidised or reduced? Why?
Is oxidation an exothermic or an endothermic reaction?
Give one example of an oxidation-reduction reaction which is also a displacement 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.
The process of respiration is ______.
Fill in the blank
Oxidation is the removal of ......................and addition of ....................
Indicate which of the following statement is true and which is false:
The removal of hydrogen from a substance is called reduction.
Name the following:
The process in which oxygen is added or hydrogen is removed.
Define an oxidation reaction.
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{CuO_{(s)} + H2_{(g)} -> Cu_{(s)} + H2O_{(l)}}\]
Give scientific reason.
It is reccommended to use air tight container for storing oil for long time.
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
In what respect does hydrogen differ from:
alkali metals
Is it essential that oxidation and reduction must occur side by side in a chemical reaction? Explain
State whether the following conversion is oxidation or reduction:
PbO2 + SO2→ PbSO4
State whether the following conversion is oxidation or reduction:
K → K+ + e-
Complete and balance the following equation:
H2 + S → ___________
Complete and balance the following equation:
Zn +_________________→ZnCl2 + H2
State what is oxidising agent. Give an example of oxidising agent in the gaseous, liquid, and solid form.
Give two test for an oxidising agent.
Give two tests for a reducing agent.
Write chemical formula for rust.
Balance the given chemical reaction as per the instructions below.
\[\ce{NaOH + H2SO4 -> Na2SO4 + H2O}\]
Oxidation means losing electrons then what is reduction?
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.
When Ag is exposed to air it gets a black coating of ____________.
Identify the reducing agent in the following reactions -
`"H"_2"O" + "F"_2 -> "HF" + "HOF"`
Identify the oxidising agent (oxidant) in the following reactions
`"Pb"_3"O"_4 + 8"HCl" -> 3"PbCl"_2 + "Cl"_2 + 4"H"_2"O"`
Identify the oxidising agent (oxidant) in the following reactions
`"V"_2"O"_5 + 5"Ca" -> 2"V" + 5"CaO"`
Identify the oxidising agent (oxidant) in the following reactions
`3"Fe" + 4"H"_2"O" -> "Fe"_3"O"_4 + 4"H"_2`
Which among the following are physical or chemical change?
Heating of an iron rod to red hot
During the reaction of some metals with dilute hydrochloric acid, following observations are made.
Some bubbles of a gas are seen when lead (Pb) is reacted with the acid.
Explain this observation giving suitable reason.
A silver article generally turns black when kept in the open for a few days. The article when rubbed with toothpaste again starts shining.
- Why do silver articles turn black when kept in the open for a few days? Name the phenomenon involved.
- Name the black substance formed and give its chemical formula.
What is a redox reaction?
The tendency of atoms to have eight electrons in the outer shell is known as ______.
The tarnishing of metals is due to the formation of ______.
What are redox reactions? Give examples.
Find the oxidation number of the element in the following compound.
Zn in ZnSO4
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
Identify the type of chemical reaction given below:
\[\ce{2Mg + O2 -> 2MgO}\]
It is recommended to use air tight containers for storing oil for a long time.
State whether the given chemical reaction is a redox reaction or not. Justify your answer.
\[\ce{MnO_2 + 4HCl->MnCl_2 +2H_2O + Cl_2}\]
A reddish brown metal used in electrical wires when powdered and heated strongly turns black. When hydrogen gas is passed over this black substance, it regains its original colour. Based on this information answer the following questions:
- Name the metal and the black substance formed.
- Write balanced chemical equations for the two reactions involved in the above information
State the change in colour observed in following case mentioning the reason:
Copper powder is strongly heated in air.
The metallic oxide which can be reduced by using common reducing agents is ______.
