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प्रश्न
Fill in the blank.
Melting of ice is a _______ change.
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उत्तर
Melting of ice is a physical change.
APPEARS IN
संबंधित प्रश्न
Changes in which new substances are formed are called ______ changes.
Complete and balance the following chemical equations:
`"H"_2"S"` + `"CI"_2` `→`
Fill in the blanK
A .............is a substance which changes the rate of a chemical reaction without undergoing a chemical change.
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Compounds, which in their molten state allow an electric current to pass through them are called
- electrolytes
- non-electrolytes
- non-conductors
- none of these
MATCH THE COLUMNS
| 1 . `H_2` + `CI_2` `→` 2HCI | a. displacement reaction |
| 2. `2FeCI_3`+ `H_2` `→` `2FeCI_2` +2HCI` | b. addition of an electronegative redical |
| 3. Fe + `CuSO_4` `→``FeSO_4` +Cu` | c. removal of an electronegative redical |
| 4. `2H_2O` +`4NO_2`+`O_2` `→` `4HNO_3` | d.reduction by adding hydrogen |
| 5. 3Fe +`3CI_2` `→` `2FeCI_3` | e.electrolysis of water |
| 6. `FeCI_3`+ 3NaOH `→``Fe(OH)_3``↓`+NaCI | F.double decomposition,precipitation reaction |
| 7.`2H_2O` `→` `2H_2``↑`+`O_2` | e. combination or synthesis reaction |
TRUE \ FALSE
A precipitation reaction takes place only in a solution.
Write true or false :
Hydrogen sulphide has rotten egg smell .
Explain the following reaction with one suitable example of Decomposition reaction
Explain the following reaction with one suitable example of Double decomposition 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)
Electron ______ is complete in each hydrogen in a hydrogen molecule.
State the type of reactions for the following represent and balance the ones that are not balanced.
Cl2 + 2KBr → 2KCl + Br2
State whether the following reaction is oxidation or reduction.
\[\ce{Na->Na+}\]
Photosynthesis is a chemical reaction that takes place in the presence of ______.
Classify the following as physical or chemical properties
Zinc dissolves in hydrochloric acid with the evolution of hydrogen gas.
Classify the following as physical or chemical properties
Most metal oxides form alkalis on interacting with water.
On heating calcium carbonate gets converted into calcium oxide and carbon dioxide.
(a) Is this a physical or a chemical change?
(b) Can you prepare one acidic and one basic solution by using the products formed in the above process? If so, write the chemical equation involved.
Iron benches kept in lawns and gardens get____________. It is a _________ change because a new _________ is formed.
Classify the following processes into physical or chemical changes:
- Beating of aluminium metal to make aluminium foil.
- Digestion of food.
- Cutting of a log of wood into pieces.
- Burning of crackers.
If you leave a piece of iron in the open for a few days, it acquires a film of brownish substance, called rust.
Do you think formation of rust from iron is a chemical change?
What is thermochemical reactions?
