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प्रश्न
Identify from the following reaction the reactants that undergo oxidation and reduction.
\[\ce{2Ag2O → 4 Ag + O2 \uparrow}\]
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उत्तर
In a reaction, silver oxide is changing to silver. That is, oxygen is being removed from silver oxide. Removal of oxygen from a substance is called reduction, so silver oxide undergoes reduction.
संबंधित प्रश्न
Define ‘redox reaction’. Give one example.
What is an oxidising agent?
Why is photosynthesis considered an endothermic reaction?
What are anti-oxidants? Why are they added to fat and oil containing foods?
In the following reaction between lead sulphide and hydrogen peroxide:
PbS (s) + 4H2O2(aq) → PbSO4(s) + 4H2O(1)
(a) which substance is reduced?
(b) Which substance is oxidised?
Identify the component oxidised in the following reaction:
H2S + Cl2 → S + 2HCl
When SO2 gas is passed through saturated solution of H2S, the following reaction occurs:
SO2 + 2H2S → 2H2O + 3S
In this reaction, which substance is oxidised and which one is reduced?
Fill in the following blanks with suitable words:
The addition of hydrogen to a substance is called ........ whereas removal of hydrogen is called .......
Explain oxidation in terms of gain or loss of oxygen with one example.
In the reaction represented by the following equation:
CuO (s) + H2 (g) → Cu (s) + H2O (1)
(a) name the substance oxidised
(b) name the substance reduced
(c) name the oxidising agent
(d) name the reducing agent
In the context of redox reactions, the removal of hydrogen from a substance is known as:
(a) oxidation
(b) dehydration
(c) reduction
(d) dehydrogenation
The process of respiration is:
(a) an oxidation reaction which is endothermic
(b) a reduction reaction which is exothermic
(c) a combination reaction which is endothermic
(d) an oxidation reaction which is exothermic
You are given the following chemical equation:
Mg (s) + CuO (s) → MgO (s) + Cu (s)
This equation represents:
(a) decomposition reaction as well as displacement reaction
(b) combination reaction as well as double displacement reaction
(c) redox reaction as well as displacement reaction
(d) double displacement reaction as well as redox reaction
Fill in the blank
Oxidation is the removal of ......................and addition of ....................
Define reduction.
TRUE \ FALSE
Hydrogen is a good oxidizing agent.
How would you change a metal like Cu into its ions?
Identify from the reaction the reactants that undergo oxidation and reduction.
Fe + S → FeS
Why this reaction is considered a reversible reaction?
Why zinc and aluminium are considered to have a unique nature. Give balanced equations to support your answer.
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
H2S + Cl2→ 2HCl + S
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
Cl2 + H2S → 2HCl + S
State whether the following conversion is oxidation or reduction:
K → K+ + e-
In the following reaction: A+ + B → A + B+. Write half-reactions for this reaction and name:
- oxidizing agent
- substance oxidized
- reducing agent
Divide the following reactions into oxidation and reduction half-reaction:
Zn + Pb2+→ Pb + Zn 2+
Name:
a substance that will reduce aqueous Iron(III)ions to iron(II)ions.
State the condition and give balanced equation for the conversion of coke to water gas.
Explain the term redox reaction with an example involving the reaction of hydrogen sulphide with chlorine.
Select the correct answer from the symbol in the bracket.
The element, which like hydrogen is a strong reducing agent.
Explain the following reaction with their balanced chemical equation.
Hydrogen sulphide reacts with sulphur dioxide.
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
`2"H"_2 + "O"_2 -> 2"H"_2"O"`
Identify the oxidising agent (oxidant) in the following reactions
`2"Mg" + "O"_2 -> 2"MgO"`
Identify the oxidising agent (oxidant) in the following reactions.
`"CuO" + "H"_2 -> "Cu" + "H"_2"O"`
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.
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.
The formation of brown colour on the freshly unit surface of vegetables and fruits is because ______ of organic compounds present in them.
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 ______.
The sum of the oxidation number of all atoms in a compound is ______.
______ is a metal that has a high resistance to corrosion.
Identify the following reactions as oxidation/reduction/redox reaction
Zn + CuSO4 → Cu + ZnSO4
Identify the following reactions as oxidation/reduction/redox reaction
CuO+H2 → Cu+H2O
What are reducing agents? Give examples.
Define oxidation number.
Find the oxidation number of the element in the following compound.
Ca in CaH2
When hydrogen gas is passed over black copper oxide, a reddish-coloured layer of copper is formed.
Answer the questions that follow based on this reaction.
- Write the equation.
- What type of reaction is it?
- Complete the blanks:
In this reaction, an oxygen atom goes away from CuO (copper oxide), which means that ______ of copper oxide takes place, whereas a hydrogen molecule takes up an oxygen atom and water (H2O) is formed, meaning ______ of hydrogen takes place.
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).
State whether the given chemical reaction is a redox reaction or not. Justify your answer.
\[\ce{MnO_2 + 4HCl->MnCl_2 +2H_2O + Cl_2}\]
The oxidizing agent in the equation \[\ce{S + 2H2SO4 -> 3SO2 + 2H2O}\] is ______.
