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प्रश्न
Name the type of chemical reaction shown by the following equation:
CaCO3 → CaO + CO2
उत्तर
CaCO3 → CaO + CO2 => Decomposition reaction
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संबंधित प्रश्न
State whether the following statement is true or false. In case a statement is false, write the corrected statement.
Iron pipes coated with zinc do not get rusted easily.
FILL IN THE BLANK
The new substances formed during a chemical reaction are called the ..................
TRUE \ FALSE
Electrolytic refining is a method in which a thin coating of a metal is done over another metal.
TRUE \ FALSE
Temperature at which a liquid starts boiling is known as the boiling point of that liquid. True or false ?
Name three reducing agents ?
Explain the type of reactions on the basis of the direction of reaction.
Choose the correct option from the bracket and explain the statement giving reason.
(Oxidation, displacement, electrolysis, reduction, zinc, copper, double displacement, decomposition)
To prevent rusting, a layer of ______ metal is applied on iron sheets.
| 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 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)
An ______ is drawn in between the reactants and products while writing the equation for 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)
Electron ______ is complete in each hydrogen in a hydrogen molecule.
Explain by writing a word equation.
Hard water gets softened on mixing with a solution of washing soda.
Show with the help of diagram of electronic configuration how the following compound is formed from the constituent atoms.
Water
Give reason for the following:
Colourless concentrated sulphuric acid in a test tube changes to blue on adding a small piece of copper to it.
State the type of reactions for the following represent and balance the ones that are not balanced.
NaOH + HCl → NaCl + H2O
Give an example of the following chemical changes.
A reaction where colour change is noticed.
State the original colour of the following substance and colour of residue obtained after heating.
Lead nitrate
Give a chemical test to distinguish between the following gases.
SO2 and Cl2
Distinguish by heating the following in dry test tubs.
Copper Sulphate and copper carbonate
Write your observation and a balanced equation in the case of the following substances being heated.
Ammonium chloride
Give reason for the following:
A characteristic change of colour is seen when a piece of iron is added to copper [II] sulphate solution.
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.
Give balanced equation for the following conversion affected by heat alone on the substance:
Copper nitrate to nitrogen dioxide
Explain the term chemical reaction with special reference to reactants and products.
______ is not a chemical change.
A thick coating of a paste of Plaster of Paris (POP) is applied over the bandage on a fractured bone. It becomes hard on drying to keep the fractured bone immobilised. Can the change in POP be reversed?
The water we drink is a combination of hydrogen and oxygen.
If you leave a piece of iron in the open for a few days, it acquires a film of brownish substance, called rust.
Can you change rust back into iron by some simple method?
Photosynthesis is a chemical charge. Justify your answer.
______ is the chemical name of limestone.
