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प्रश्न
What do you observe when :
an iron nail is kept in tap water for few days
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उत्तर
We observe reddish brown coating on the nail called rust (entirely new substance) is chemical change.
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संबंधित प्रश्न
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer
Which of the following is a reducing agent?
- oxygen
- chlorine
- hydrogen
- none of these
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Miscible liquids having slightly different boiling points can be separated by the
- evaporation
- distillation
- fractional distillation
- sedimentation
Write true or false.
A chemical equation gives only qualitative information of a chemical reaction.
Complete the statement by filling the gaps using appropriate term from the terms given in the bracket.
(slow, coloured, arrow, fast, smell, milky, physical, product, chemical, reactant, covalent, ionic, octet, duplet, exchange, sharing, equality sign)
Rusting of iron is a ______ chemical change.
Complete the statement by filling the gaps using appropriate term from the terms given in the bracket.
(slow, coloured, arrow, fast, smell, milky, physical, product, chemical, reactant, covalent, ionic, octet, duplet, exchange, sharing, equality sign)
The spoiling of food is a chemical change which is recognized from the generation of certain ______ due to it.
Choose the correct option from the bracket and explain the statement giving reason.
(Oxidation, displacement, electrolysis, reduction, zinc, copper, double displacement, decomposition)
The conversion of ferrous sulphate to ferric sulphate is ______ reaction.
Give an example of a reaction where the following are involved
Electricity
What do you understand by precipitation reaction? Explain with examples.
Multiple choice:
Which of the following is not a characteristic of a chemical change?
Give a chemical test to distinguish between the following gases.
CO2 and SO2
Give reason for the following:
A characteristic change of colour is seen when a piece of iron is added to copper [II] sulphate solution.
Complete the table given below.
| Heat on ammonium dichromate | Name of neutral gas evolved |
Give a suitable example with an equation to show the representation of a chemical reaction.
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
Calcium hydroxide.
Explain the following statement: Digestion is a chemical change.
Higher order Thinking question
Peeled and unpeeled banana does not look the same. Does that mean peeling banana is a chemical change?
Anaerobic bacteria digest animal waste and produce biogas (Change – A). The biogas is then burnt as fuel (Change – B). The following statements pertain to these changes. Choose the correct one.
Match the following:
| 1. | Sodium Chloride | a. | CaSO41/2H2O |
| 2. | Calcium sulphate dihydrate | b. | C2H5Oh |
| 3. | Magnesium sulphate hydrate | c. | CaSO4.2H2O |
| 4. | Calcium sulphate hemihydrate | d. | NaCl |
| 5. | Phenol | e. | MgSO4.H2O |
Write some materials prepared by chemical changes.
When carbon dioxide is passed through lime water ______.
