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प्रश्न
The chemical formula for rust is.............. .
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उत्तर
The chemical formula for rust is Fe2O3. x H2O
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संबंधित प्रश्न
Define ‘redox reaction’. Give one example.
Which of the statements about the reaction below are incorrect?
\[\ce{2PbO(s) + C(s) → 2Pb(s) + CO2(g)}\]
- Lead is getting reduced.
- Carbon dioxide is getting oxidised.
- Carbon is getting oxidised.
- Lead oxide is getting reduced.
Explain the following in term Oxidation of gain or loss of oxygen with two example.
Write the chemical formula of rust.
Why is photosynthesis considered an endothermic reaction?
Identify the component oxidised in the following reaction:
\[\ce{H2S + Cl2 -> S + 2HCl}\]
The addition of oxygen to a substance is called ______ whereas removal of oxygen 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.
Is oxidation an exothermic or an endothermic reaction?
Explain the following in terms of gain or loss of oxygen with one example:
Reduction
Define the following in terms of gain or loss of hydrogen with one example:
Reduction
When a magnesium ribbon is heated, it burns in air to form magnesium oxide. Write a balanced chemical equation for this reaction. Name
- substance oxidised, and
- substance reduced.
Hydrogen burns with a ______ flame and ______ sound is heard.
Explain the following in term Reduction of gain or loss of oxygen with two example.
Electrolysis is a redox process. Explain.
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.
Reduction
Why zinc and aluminium are considered to have a unique nature. Give balanced equations to support your answer.
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.
Mg + 2HCl → MgCl2 + H2
State whether the following conversion is oxidation or reduction:
Cu2+ + 2 e-→ Cu
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
Write the equation in the ionic form
CuSO4(aq) + Fe(s)→ FeSO4(aq) + Cu(s)
A metal oxide that is reduced by hydrogen is
Name:
an oxidizing agent that does not contain oxygen.
Name:
a solid that is an oxidizing agent.
Complete and balance the following equation:
Zn +_________________→ZnCl2 + H2
State the condition and give balanced equation for the conversion of coke to water gas.
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.
Explain the following reaction with their balanced chemical equation.
Hydrogen sulphide reacts with sulphur dioxide.
Identify the following reactions as oxidation or reduction
- Na → Na+ + e
- Fe3+ + 2 e- → Fe+
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.
The process of reduction involves ____________.
Select the oxidising agent for the following reaction:
\[\ce{H2S + I2 -> 2HI + S}\]
Identify the reducing agent in the following reactions -
`"H"_2"O" + "F"_2 -> "HF" + "HOF"`
Identify the reducing agent in the following reactions
`"Fe"_2"O"_3 + 3"CO" -> 2"Fe" + 3"CO"_2`
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
`2"Mg" + "O"_2 -> 2"MgO"`
Identify the oxidising agent (oxidant) in the following reactions
`"CuSO"_4 + "Zn" -> "Cu" + "ZnSO"_4`
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
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.
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.
Write a short note on oxidizing and reducing agents.
The tarnishing of metals is due to the formation of ______.
______ is a metal that has a high resistance to corrosion.
Choose the odd one out and write the reason:
Identify the following reactions as oxidation/reduction/redox reaction
2Mg +O2 → 2MgO
What is rancidity?
Define oxidation number.
Find the oxidation number of the element in the following compound.
Zn in ZnSO4
Identify the type of chemical reaction given below:
\[\ce{2Mg + O2 -> 2MgO}\]
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
