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प्रश्न
Write chemical formula for rust.
उत्तर
Chemical formula for rust: Fe2O3•xH2O
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संबंधित प्रश्न
Define ‘redox reaction’. Give one example.
The chemical formula for rust is.............. .
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.
Write the chemical formula of rust.
Why is photosynthesis considered an endothermic reaction?
Give one example of an oxidation-reduction reaction which is also a combination reaction.
In the reaction represented by the following equation:
CuO (s) + H2 (g) → Cu (s) + H2O (1)
(a) name the substance oxidised
(b) name the substance reduced
(c) name the oxidising agent
(d) name the reducing agent
Hydrogen burns with a ______ flame and ______ sound is heard.
Define redox reaction.
Electrolysis is a redox process. Explain.
Explain the following in term of gain or loss of oxygen with two examples.
Reduction
In what respect does hydrogen differ from:
alkali metals
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 whether the following conversion is oxidation or reduction:
2Cl- - e-→ Cl2
For the reaction PbO + H2→ Pb + H2O, which of the following statements is wrong?
Name:
an oxidizing agent that does not contain oxygen.
Name:
a gas that is oxidizing as well as a reducing agent.
Define Oxidation reaction.
Explain the term reduction in term of addition and removal of oxygen/hydrogen with a suitable example.
State what is reducing agent. Give an example of oxidising agent in the gaseous, liquid, and solid form.
When Ag is exposed to air it gets a black coating of ____________.
Select the oxidising agent for the following reaction:
\[\ce{H2S + I2 -> 2HI + S}\]
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`
Which among the following are physical or chemical change?
Heating of an iron rod to red hot
Zinc liberates hydrogen gas when reacted with dilute hydrochloric acid whereas copper does not. Explain why?
The formation of brown colour on the freshly unit surface of vegetables and fruits is because ______ of organic compounds present in them.
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
Zn + CuSO4 → Cu + ZnSO4
Identify the following reactions as oxidation/reduction/redox reaction
2Mg +O2 → 2MgO
Find the oxidation number of the element in the following compound.
Zn in ZnSO4
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.
The metallic oxide which can be reduced by using common reducing agents is ______.
