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प्रश्न
A chemical equation is a statement that describes a chemical change in terms of
विकल्प
symbols and formulae
energy
number of atoms
colours
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उत्तर
symbols and formulae.
APPEARS IN
संबंधित प्रश्न
State whether the following statement is true or false. In case a statement is false, write the corrected statement.
Formation of manure from leaves is a physical change.
When carbon dioxide is passed through lime water, it turns milky due to the formation of ______.
Give a reason.
Wasp sting is treated with vinegar.
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 |
| Reactants | Products | Type of chemical reaction |
| BaCl2(aq) + ZnSO4(aq) | H2CO3(aq) | Displacement |
| 2AgCl(s) | FeSO4(aq) + Cu(s) | Combination |
| CuSO4(aq) + Fe(s) | BaSO4↓ + ZnCl2(aq) | Decomposition |
| H2O(l) + CO2(g) | 2Ag(s) + Cl2(g) | Double displacement |
Complete the statement by filling the gap using an 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)
An ______ is drawn in between the reactants and products while writing the equation for a chemical reaction.
Match the pairs.
| a. | Photosynthesis | i. | Tendency to lose electrons |
| b. | Water | ii. | Reactant in combustion process |
| c. | Sodium chloride | iii. | Chemical change |
| d. | Dissolution of salt in water | iv. | Covalent bond |
| e. | Carbon | v. | Ionic bond |
| f. | Fluorine | vi. | Physical change |
| g. | Magnesium | vii. | Tendency to form anion |
State the conditions necessary for a chemical change or reaction.
Give an example of a reaction where the following are involved:
Solution
Multiple choice:
A reaction of a type: AB + CD → AD + CD, involves
Complete and balance the following reaction:
\[\ce{CuCO3 ->[\Delta]}\]
Complete and balance the following reaction:
\[\ce{Pb(NO3)2 ->[\Delta]}\]
What do you observe when dilute sulphuric acid is added to the following:
Sodium Sulphide
Write your observation and a balanced equation in the case of the following substances being heated.
Copper nitrate.
Give examples of exothermic reactions i.e. heat evolved in each of the following:
(a) reaction between a solid and a liquid
(b) reaction between two gases
Give two examples of exothermic reactions seen in everyday life.
Name the following:
The type of change physical or chemical involved – ‘during respiration in human beings’.
The changes in which new substance with new chemical properties are formed are ______.
State whether the following statement is true or false:
When a candle burns, both physical and chemical changes take place.
Write the equation for the process of formation of rust.
The reaction of H2 gas with oxygen gas to form water is an example of ______.
