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प्रश्न
Write true or false.
A chemical equation gives only qualitative information of a chemical reaction.
विकल्प
True
False
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उत्तर
False
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संबंधित प्रश्न
Complete and balance the following chemical equations:
Fe `"SO"_4` + NaOH `→`
(aq.) (aq.)
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
Evaporation of water is a physical change. True or false ?
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 the following chemical change.
A reaction where colour change is noticed
Name affects the acidified K2Cr2O7 paper and also turns lime water dirty milky.
State the original colour of the following substance and colour of residue obtained after heating.
Copper carbonate
Select the correct answer for the following options:
The gas obtained when potassium chlorate is heated in the presence of a catalyst.
Give reason for the following:
Electrolytic decomposition of water is a reaction involving change of state.
A chemical reaction is often accompanied by external indications or characteristics which include –
- Colour change
- Effervescence or gas evolved
- Evolution or absorption of heat
- Formation of a precipitate.
With reference to each of the above indications, state the external indication seen during – Addition of dilute acid to an active metal.
NPK are the primary nutrients for plants.
Explain the following statement: Digestion is a chemical change.
Burning of paper is the best example of ______ change.
Arrange the following statements in correct sequence:
- One side is water-loving and other water-hating molecules.
- When you agitate the cloth, the dirt is surrounded by many molecules and taken away from the cloth.
- The dirt surrounded by the detergent molecules floats in the water making it dirty.
- Finally, the cloth is clean.
- The detergent molecules have two sides.
- Water hating goes and joins with dirt and oil in the cloth while the water-loving joins with the water molecules.
Which of the following are chemical changes?
(i) Decaying of wood
(ii) Burning of wood
(iii) Sawing of wood
(iv) Hammering of a nail into a piece of wood
Classify each of the following, as a physical or a chemical change. Give reasons.
(a) Drying of a shirt in the sun.
(b) Rising of hot air over a radiator.
(c) Burning of kerosene in a lantern.
(d) Change the colour of black tea by adding lemon juice to it.
(e) Churning of milk cream to get butter.
State whether the following statement is true or false:
When a candle burns, both physical and chemical changes take place.
The chemical name of baking soda is sodium bicarbonate.
Which is used as a catalyst during the process of hydrogenation of oils?
When milk is mixed with coffee decoction, the colour of milk and decoction changes due to ______.
