Advertisements
Advertisements
प्रश्न
What is meant by rust?
उत्तर
Iron reacts with moist air to acquire a coating of a brown flaky substance called rust.
APPEARS IN
संबंधित प्रश्न
The chemical formula for rust is.............. .
What is an oxidising agent?
Why does the colour of copper sulphate solution change when an iron nail is dipped in it?
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.
What are anti-oxidants? Why are they added to fat and oil containing foods?
What is an oxidation reaction? Identify in the following reaction (i) the substance oxidised, and (ii) the substance reduced:
ZnO + C → Zn + CO
When a magnesium ribbon burns in air with a dazzling flame and forms a white ash, is magnesium oxidised or reduced? Why?
Define reduction.
MULTIPLE CHOICE QUESTIONS
The process of adding oxygen to a substance is called
- oxidation.
- reduction.
- displacement.
- hydrogenation.
TRUE \ FALSE
Hydrogen is a good oxidizing agent.
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{CuO(s) + H2(g) -> Cu(s) + H2O (l)}\]
Compare hydrogen and halogens on the basis of:
reaction with oxygen
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:
Cu2+ + 2 e-→ Cu
Divide the following reactions into oxidation and reduction half-reaction:
Zn + Pb2+→ Pb + Zn 2+
Divide the above equation into oxidation and reduction half-reactions.
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.
Name:
a gas that is oxidizing as well as a reducing agent.
Define Oxidation reaction.
State a reason why, when hydrogen is passed over heated copper oxide, the resultant product formed, differs in colour from the original reactant.
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.
When the positive charge on an ion increases or the negative charge on them decreases it is called as _______.
Explain the following reaction with their balanced chemical equation.
Hydrogen sulphide reacts with sulphur dioxide.
Find the oxidation number of the elements in the following compounds.
- C in CO2
- Mn in MnSO4
- N in HNO3
Select the oxidising agent for the following reaction:
\[\ce{H2S + I2 -> 2HI + S}\]
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
`3"Fe" + 4"H"_2"O" -> "Fe"_3"O"_4 + 4"H"_2`
Which among the following are physical or chemical change?
Evaporation of petrol
Mention some oxidation reactions that occur in daily life.
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).
The oxidizing agent in the equation \[\ce{S + 2H2SO4 -> 3SO2 + 2H2O}\] is ______.
