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प्रश्न
Complete and balance the following chemical equations:
N2 + O2 →
उत्तर
N2 + O2 → 2NO(g)
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संबंधित प्रश्न
When carbon dioxide is passed through lime water, it turns milky due to the formation of ______.
Changes in which new substances are formed are called ______ changes.
Fill in the blanK
A .............is a substance which changes the rate of a chemical reaction without undergoing a chemical change.
Classify the following reaction as combination, decomposition, displacement, precipitation and neutralization. Also balance the equation.
\[\ce{NH3_{(g)} + HCl_{(g)} -> NH4Cl_{(s)}}\]
Write the missing reactants and products and balance the equations.
NaOH + ............... `→` NaCI + ...................
What do you observe when Iron nail is kept in copper sulphate solution for sometime.
FILL IN THE BLANK
On reaction with sulphuric acid solution, barium chloride forms a white precipitate of ........ sulphate.
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
Ammonia is a good oxidizing agent.
How is precipitate formation in a chemical reaction indicated?
Is kerosene an electrolyte or a non-electrolyte ?
Define chemical reaction.
Fill in the blank:
The substances formed as a result of a chemical reaction are called _______
Write true or false .
A black residue is formed when sugar is heated .
Explain by writing a word equation.
Hard water gets softened on mixing with a solution of washing soda.
Give an example of the following chemical change.
Two gases combine to form white solid
Give reason for the following:
Silver nitrate solution is kept in coloured bottles.
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.
Complete the table given below.
| Heat on sodium chloride | Colour imparted to flame during flame test |
Explain the term chemical reaction with special reference to reactants and products.
Give a balanced equation for a reaction involving the evolution of gas on the addition of dilute acid to calcium carbonate.
Explain with the help of balanced equations, how precipitation reactions are used for identifying the positive radicals in three different salts, each having a different cation [positive ion].
True or False. If false, give the correct answer.
Taking a glass of water and freezing it by placing it in the freezer is a chemical change.
Chemical change is a temporary 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.
A chemical change may involve –
Classify the following processes into physical or chemical changes:
(i) Beating of aluminium metal to make aluminium foil.
(ii) Digestion of food.
(iii) Cutting of a log of wood into pieces.
(iv) 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 the formation of rust from iron is a chemical change?
Iron and rust are the same substances.
When milk is mixed with coffee decoction, the colour of milk and decoction changes due to ______.
