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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
The chemical formula for rust is.............. .
What is an oxidising agent?
Define corrosion.
Identify the component oxidised in the following reaction:
\[\ce{H2S + Cl2 -> S + 2HCl}\]
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?
The addition of oxygen to a substance is called ______ whereas removal of oxygen is called ______.
When a magnesium ribbon burns in air with a dazzling flame and forms a white ash, is magnesium oxidised or reduced? Why?
Is oxidation an exothermic or an endothermic reaction?
Give one example of an oxidation-reduction reaction which is also a combination reaction.
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
Fill in the blank
Oxidation is the removal of ......................and addition of ....................
Indicate which of the following statement is true and which is false:
The removal of hydrogen from a substance is called reduction.
Explain the following in term Reduction of gain or loss of oxygen with two example.
Give scientific reason.
It is reccommended to use air tight container for storing oil for long time.
In what respect does hydrogen differ from:
alkali metals
Give the general group study of hydrogen with reference to
burning
Why this reaction is considered a reversible reaction?
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-
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 + Cu2+ → Cu + Zn 2+
For the reaction PbO + H2→ Pb + H2O, which of the following statements is wrong?
Name:
a substance that will reduce aqueous Iron(III)ions to iron(II)ions.
Complete and balance the following equation:
CuO +__________→ Cu +___________
State the condition and give balanced equation for the conversion of coke to water gas.
Explain the term reduction in term of addition and removal of oxygen/hydrogen with a suitable example.
State what is oxidising agent. Give an example of oxidising agent in the gaseous, liquid, and solid form.
Select the correct answer from the symbol in the bracket.
The element, which like hydrogen is a strong reducing agent.
Oxidising agents are also called as ______ because they remove electrons form other substances.
Oxidation is a process which involves ____________.
\[\ce{MnO2 + 4HCl -> + 2H2O + Cl2}\]
Identify the substance oxidized in the above equation.
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 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
`"CuSO"_4 + "Zn" -> "Cu" + "ZnSO"_4`
Identify the oxidising agent (oxidant) in the following reactions
`3"Fe" + 4"H"_2"O" -> "Fe"_3"O"_4 + 4"H"_2`
Grapes hanging on the plant do not ferment but after being plucked from the plant can be fermented. Under what conditions do these grapes ferment? Is it a chemical or a physical change?
Which among the following are physical or chemical change?
Evaporation of petrol
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.
Zinc liberates hydrogen gas when reacted with dilute hydrochloric acid whereas copper does not. Explain why?
A silver article generally turns black when kept in the open for a few days. The article when rubbed with toothpaste again starts shining.
- Why do silver articles turn black when kept in the open for a few days? Name the phenomenon involved.
- Name the black substance formed and give its chemical formula.
Write a short note on oxidizing and reducing agents.
The formation of brown colour on the freshly unit surface of vegetables and fruits is because ______ of organic compounds present in them.
______ 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
Zn + CuSO4 → Cu + ZnSO4
Identify the following reactions as oxidation/reduction/redox reaction
CuO+H2 → Cu+H2O
Find the oxidation number of the element in the following compound.
A1 in AlCl3
Identify the type of chemical reaction given below:
\[\ce{2Mg + O2 -> 2MgO}\]
In the redox reaction:
MnO2 + 4HCl → MnCl2 + 2H2O + Cl2
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
Metals are good ______.
