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प्रश्न
Identify from the reaction the reactants that undergo oxidation and reduction.
Fe + S → FeS
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उत्तर १
Fe + S → FeS
In a reaction, Fe is changing to FeS. That means, iron loses electrons to form FeS. Loss of electron from a substance is called oxidation, so iron undergoes oxidation.
उत्तर २
Iron (Fe) undergoes oxidation and Sulphur (S) undergoes reduction.
संबंधित प्रश्न
Corrosion can be prevented by using ……………. solution.
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{4Na(s) + O2(g) -> 2Na2O(s)}\]
Explain the following in term Oxidation of gain or loss of oxygen with two example.
Define corrosion.
What is meant by rust?
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
Fill in the following blanks with suitable words:
The addition of oxygen to a substance is called ......... whereas removal of oxygen is called ........
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.
Give an example of an oxidation reaction.
Is oxidation an exothermic or an endothermic reaction?
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.
Fill in the blank
Oxidation is the removal of ......................and addition of ....................
Name the following:
The process in which oxygen is added or hydrogen is removed.
Identify from the following reaction the reactants that undergo oxidation and reduction.
\[\ce{2Ag2O → 4 Ag + O2 \uparrow}\]
Give the general group study of hydrogen with reference to
reducing power
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.
PbO + CO → Pb + CO2
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
Mg + 2HCl → MgCl2 + H2
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
H2S + Cl2→ 2HCl + S
State whether the following conversion is oxidation or reduction:
PbO2 + SO2→ PbSO4
State whether the following conversion is oxidation or reduction:
2Cl- - e-→ Cl2
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+
Divide the following reactions into oxidation and reduction half-reaction:
Cl2 + 2Br- → Br2 + 2Cl-
Reacting with water, an active metal produces
Which of the following statements about hydrogen is incorrect?
Name:
a substance that oxidizes concentrated HCl to chlorine.
Name:
a substance that will reduce aqueous Iron(III)ions to iron(II)ions.
Name:
a liquid that is an oxidizing agent as well as a reducing agent.
State a reason why, when hydrogen is passed over heated copper oxide, the resultant product formed, differs in colour from the original reactant.
With reference to oxidation & reduction reaction – complete the statement given by filling in the blanks with only the words (a) Addition (b) Removal.
‘Oxidation is a chemical reaction involving ____ of oxygen to a substance or ____ of hydrogen from a substance. Reduction on the otherhand involves ____ of hydrogen to a substance or ____ of oxygen from a substance.
State what is reducing agent. Give an example of oxidising agent in the gaseous, liquid, and solid form.
Give two tests for a reducing agent.
Write chemical formula for rust.
When Ag is exposed to air it gets a black coating of ____________.
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
`2"Mg" + "O"_2 -> 2"MgO"`
Which among the following are physical or chemical change?
Curding of milk
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 temperature of the reaction mixture rises when aluminium (Al) is added.
Explain this observation giving suitable reason.
Why do we store silver chloride in a dark coloured bottle?
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?
Mention some oxidation reactions that occur in daily life.
The tarnishing of metals is due to the formation of ______.
The tarnishing of metals is an example of ______ reaction.
The sum of the oxidation number of all atoms in a compound is ______.
______ is a metal that has a high resistance to corrosion.
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
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).
Metals are good ______.
The metallic oxide which can be reduced by using common reducing agents is ______.
