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प्रश्न
Which among the following are physical or chemical change?
Heating of an iron rod to red hot
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उत्तर
Physical
APPEARS IN
संबंधित प्रश्न
Why does the colour of copper sulphate solution change when an iron nail is dipped in it?
Define corrosion.
Fill in the following blanks with suitable words:
The addition of oxygen to a substance is called ......... whereas removal of oxygen is called ........
Give one example of an oxidation-reduction reaction which is also a displacement reaction.
Name the following:
The process in which oxygen is added or hydrogen is removed.
TRUE \ FALSE
Hydrogen is a good oxidizing agent.
Identify the substances that are oxidised and the substances that are reduced in the following reaction.
\[\ce{CuO_{(s)} + H2_{(g)} -> Cu_{(s)} + H2O_{(l)}}\]
Give scientific reason.
It is reccommended to use air tight container for storing oil for long time.
Complete and balance the following equation:
H2 + S → ___________
State what is reducing 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.
In the reaction of iron with copper sulphate solution:
CuSO4 + Fe → Cu + FeSO4
Which option in the given table correctly represents the substance oxidized and the reducing agent?
| OPTION | Substance Oxidized | Reducing Agent |
| A | Fe | Fe |
| B | Fe | FeSO4 |
| C | Cu | Fe |
| D | CuSO4 | Fe |
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?
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?
The sum of the oxidation number of all atoms in a compound is ______.
Choose the odd one out and write the reason:
Find the oxidation number of the element in the following compound.
Ca in CaH2
Identify the type of chemical reaction given below:
\[\ce{2Mg + O2 -> 2MgO}\]
The metallic oxide which can be reduced by using common reducing agents is ______.
