Advertisements
Advertisements
Question
When the positive charge on an ion increases or the negative charge on them decreases it is called as _______.
Options
reduction
corrosion
oxidation
decomposition
Advertisements
Solution
When the positive charge on an ion increases or the negative charge on them decreases it is called as oxidation.
APPEARS IN
RELATED QUESTIONS
Define ‘redox reaction’. Give one example.
What is an oxidising agent?
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.
A shiny brown-coloured element ‘X’ on heating in air becomes black in colour. Name the element ‘X’ and the black-colored compound formed.
What is meant by rust?
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?
Identify the component oxidised in the following reaction:
\[\ce{H2S + Cl2 -> S + 2HCl}\]
The addition of hydrogen to a substance is called ______ whereas removal of hydrogen is called ______.
When a magnesium ribbon burns in air with a dazzling flame and forms a white ash, is magnesium oxidised or reduced? Why?
Give an example of an oxidation reaction.
When copper powder is heated strongly in air, it forms copper oxide. Write a balanced chemical equation for this reaction. Name
- substance oxidised, and
- substance reduced.
Define the following in terms of gain or loss of hydrogen with one example:
Reduction
The process of respiration is ______.
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 following reaction the reactants that undergo oxidation and reduction.
\[\ce{2Ag2O → 4 Ag + O2 \uparrow}\]
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 with alkali metals on the basis of:
Oxide formation
Give the general group study of hydrogen with reference to
reducing power
Compare hydrogen and halogens on the basis of:
reaction with oxygen
Why zinc and aluminium are considered to have a unique nature. Give balanced equations to support your answer.
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
H2S + Cl2→ 2HCl + S
State, giving reason, whether the substances printed in bold letters have been oxidized or reduced.
Cl2 + H2S → 2HCl + S
State whether the following conversion is oxidation or reduction:
Cu2+ + 2 e-→ Cu
Write the equation in the ionic form
CuSO4(aq) + Fe(s)→ FeSO4(aq) + Cu(s)
Which of the following statements about hydrogen is incorrect?
Name:
a liquid that is an oxidizing agent as well as a reducing agent.
Name:
a gas that is oxidizing as well as a reducing agent.
Complete and balance the following equation:
H2 + S → ___________
Complete and balance the following equation:
\[\ce{K + H2O -> }\]________+ ________
State the condition and give balanced equation for the conversion of coke to water gas.
Oxidising agents are also called as ______ because they remove electrons form other substances.
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.
When Ag is exposed to air it gets a black coating of ____________.
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`
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.
Some bubbles of a gas are seen when lead (Pb) is reacted with the acid.
Explain this observation giving suitable reason.
What happens when zinc granules are treated with dilute solution of H2SO4, HCl, HNO3, NaCl and NaOH Also write the chemical equations if reaction oçcurs.
On adding a drop of barium chloride solution to an aqueous solution of sodium sulphite, white precipitate is obtained :
- Write a balanced chemical equation for the reaction involved.
- What other name can be given to this precipitation reaction?
- On adding dilute hydrochloric acid to the reaction mixture, white precipitate disappears. Why?
Mention some oxidation reactions that occur in daily life.
Identify the following reactions as oxidation/reduction/redox reaction
2Mg +O2 → 2MgO
Define oxidation number.
Find the oxidation number of the element in the following compound.
Mg in MgO
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).
It is recommended to use air tight containers for storing oil for a long time.
In the redox reaction:
MnO2 + 4HCl → MnCl2 + 2H2O + Cl2
The metallic oxide which can be reduced by using common reducing agents is ______.
