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प्रश्न
Give an example of a reaction where the following are involved
Catalyst
उत्तर
\[\ce{2KCIO3_ ->[MnO2] 2KCI + 3O2}\]
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संबंधित प्रश्न
The chemical name of baking soda is ______.
Changes in which new substances are formed are called ______ changes.
Write true or false :
Hydrogen sulphide has rotten egg smell .
What is the reaction called when oxidation and reduction take place simultaneously? Explain with one example.
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)
The white particles of baking soda disappear when put in lemon juice. This means that it is a ______ change.
State the conditions necessary for a chemical change or reaction.
Define the following terms
Precipitate
Multiple choice:
Which of the following is not a characteristic of a chemical change?
Multiple choice:
Thermal decomposition of sodium carbonate will produce
What do you observe? When
Barium chloride is added to sodium sulphate solution
What do you observe when dilute sulphuric acid is added to the following:
Sodium Sulphide
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.
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 – Thermal decomposition of mercury [II] oxide.
On heating which of the following substances i.e. copper carbonate, zinc carbonate, washing soda, copper sulphate, zinc nitrate, copper nitrate, lead nitrate, ammonium chloride and ammonium dichromate – relate to the reaction given below.
A coloured substance which leaves a black residue and evolves two gases one of which is acidic and coloured and the other neutral and colourless.
State the following reaction represent oxidation or reduction.
\[\ce{Fe++->Fe+++}\]
Give a balanced equation for the conversion of an ammonium salt to a basic gas.
Limestone contains ______ mainly.
Beating an egg to make a cake is a ______.
Match the following:
| Column I | Column II | ||
| 1. | Burning of coal | a. | Rusting |
| 2. | Painting of a surface | b. | Evaporation |
| 3. | Dipping iron in the water | c. | Chemical change |
| 4. | Salt from seawater | d. | Prevention of rusting |
Write a note on the following:
Fermentation
