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प्रश्न
Which among the following are physical or chemical change?
Sublimation of solid ammonium chloride
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उत्तर
Physical
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संबंधित प्रश्न
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{4Na(s) + O2(g) -> 2Na2O(s)}\]
Explain the following in term Oxidation of gain or loss of oxygen with two example.
Why is photosynthesis considered 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:
Oxidation
Name the following:
The process in which oxygen is added or hydrogen is removed.
Electrolysis is a redox process. Explain.
Identify from the reaction the reactants that undergo oxidation and reduction.
Fe + S → FeS
State whether the following conversion is oxidation or reduction:
2Cl- - e-→ Cl2
Divide the following reactions into oxidation and reduction half-reaction:
Zn + Pb2+→ Pb + Zn 2+
A metal oxide that is reduced by hydrogen is
Complete and balance the following equation:
\[\ce{K + H2O -> }\]________+ ________
Complete and balance the following equation:
Fe + H2O →___________+____________
Select the oxidising agent for the following reaction:
\[\ce{H2S + I2 -> 2HI + S}\]
Which among the following are physical or chemical change?
Heating of an iron rod to red hot
The tarnishing of metals is due to the formation of ______.
The sum of the oxidation number of all atoms in a compound is ______.
Choose the odd one out and write the reason:
When hydrogen gas is passed over black copper oxide, a reddish-coloured layer of copper is formed.
Answer the questions that follow based on this reaction.
- Write the equation.
- What type of reaction is it?
- Complete the blanks:
In this reaction, an oxygen atom goes away from CuO (copper oxide), which means that ______ of copper oxide takes place, whereas a hydrogen molecule takes up an oxygen atom and water (H2O) is formed, meaning ______ of hydrogen takes place.
State the change in colour observed in following case mentioning the reason:
Copper powder is strongly heated in air.
