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प्रश्न
Write the chemical formula of rust.
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उत्तर
Rust is hydrated iron (III) oxide (Fe2O3.xH2O).
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संबंधित प्रश्न
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{4Na(s) + O2(g) -> 2Na2O(s)}\]
Define corrosion.
Why is photosynthesis considered an endothermic reaction?
The addition of oxygen to a substance is called ______ whereas removal of oxygen is called ______.
The addition of hydrogen to a substance is called ______ whereas removal of hydrogen is called ______.
Is oxidation an exothermic or an endothermic reaction?
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:
Reduction
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.
Define the following in terms of gain or loss of hydrogen with one example:
Oxidation
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 ______.
Hydrogen burns with a ______ flame and ______ sound is heard.
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.
Define reduction.
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{CuO_{(s)} + H2_{(g)} -> Cu_{(s)} + H2O_{(l)}}\]
The electron releasing tendency of zinc is ______ than that of copper.
How would you change a metal like Cu into its ions?
Give scientific reason.
It is reccommended to use air tight container for storing oil for long time.
Identify from the reaction the reactants that undergo oxidation and reduction.
Fe + S → FeS
Identify from the reaction the reactants that undergo oxidation and reduction.
\[\ce{NiO + H2 -> Ni + H2O}\]
Explain the following in term of gain or loss of oxygen with two examples.
Oxidation
Explain the following in term of gain or loss of oxygen with two examples.
Reduction
State whether the following conversion is oxidation or reduction:
Cu2+ + 2 e-→ Cu
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:
a substance that will reduce aqueous Iron(III)ions to iron(II)ions.
Complete and balance the following equation:
Fe + H2O →___________+____________
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.
Select the correct answer from the symbol in the bracket.
The element, which like hydrogen is a strong reducing agent.
Balance the given chemical reaction as per the instructions below.
\[\ce{NaOH + H2SO4 -> Na2SO4 + H2O}\]
Oxidation means losing electrons then what is reduction?
Find the oxidation number of the elements in the following compounds.
- C in CO2
- Mn in MnSO4
- N in HNO3
The process of reduction involves ____________.
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
`"CuSO"_4 + "Zn" -> "Cu" + "ZnSO"_4`
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.
`"CuO" + "H"_2 -> "Cu" + "H"_2"O"`
Which among the following are physical or chemical change?
Heating of an iron rod to red hot
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.
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?
Choose the odd one out and write the reason:
Identify the following reactions as oxidation/reduction/redox reaction
CuO+H2 → Cu+H2O
What are reducing agents? Give examples.
What are redox reactions? 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.
Mg in MgO
Identify the type of chemical reaction given below:
\[\ce{2Mg + O2 -> 2MgO}\]
In the redox reaction:
MnO2 + 4HCl → MnCl2 + 2H2O + Cl2
