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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
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.
Write the chemical formula of rust.
What are anti-oxidants?
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?
The addition of hydrogen to a substance is called ______ whereas removal of hydrogen is called ______.
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
Explain the following in terms of gain or loss of oxygen with one example:
Reduction
In order to prevent the spoilage of potato chips, they are packed in plastic bags in an atmosphere of ______.
The process of respiration is ______.
Fill in the blank
In redox reaction oxidation and reduction occur ............................
Name the following:
The process in which oxygen is added or hydrogen is removed.
Define reduction.
MULTIPLE CHOICE QUESTIONS
The process of adding oxygen to a substance is called
- oxidation.
- reduction.
- displacement.
- hydrogenation.
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{CuO_{(s)} + H2_{(g)} -> Cu_{(s)} + H2O_{(l)}}\]
Identify from the reaction the reactants that undergo oxidation and reduction.
2Mg + O2 → 2MgO
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
Compare hydrogen and halogens on the basis of:
reaction with oxygen
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.
Describe briefly the ionic concept of oxidation and reduction. Give an equation to illustrate.
Is it essential that oxidation and reduction must occur side by side in a chemical reaction? Explain
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
PbO + CO → Pb + CO2
State whether the following conversion is oxidation or reduction:
K → K+ + e-
Write the equation in the ionic form
CuSO4(aq) + Fe(s)→ FeSO4(aq) + Cu(s)
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 oxidizes concentrated HCl to chlorine.
Name:
a substance that will reduce aqueous Iron(III)ions to iron(II)ions.
Complete and balance the following equation:
H2 + S → ___________
State a reason why, when hydrogen is passed over heated copper oxide, the resultant product formed, differs in colour from the original reactant.
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.
Oxidising agents are also called as ______ because they remove electrons form other substances.
Find the oxidation number of the elements in the following compounds.
- C in CO2
- Mn in MnSO4
- N in HNO3
Rusting of iron involves a chemical reaction which is a combination of:
Oxidation is a process which involves ____________.
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?
Evaporation of petrol
Which among the following are physical or chemical change?
Burning of Liquefied Petroleum Gas (LPG)
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 tendency of atoms to have eight electrons in the outer shell is known as ______.
The tarnishing of metals is an example of ______ reaction.
Choose the odd one out and write the reason:
Identify the following reactions as oxidation/reduction/redox reaction
CuO+H2 → Cu+H2O
Find the oxidation number of the element in the following compound.
N in NH3
Identify the type of chemical reaction given below:
\[\ce{2Mg + O2 -> 2MgO}\]
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 the change in colour observed in following case mentioning the reason:
Copper powder is strongly heated in air.
