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प्रश्न
Fill in the blank
A catalyst either ................or ............... the rate of a chemical change but itself remains ............... at the end of the reaction.
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उत्तर
A catalyst either increases or decreases the rate of a chemical change but itself remains unchanged at the end of the reaction.
APPEARS IN
संबंधित प्रश्न
The chemical name of baking soda is ______.
What do you observe when iron nail is kept in copper sulphate solution for sometime.
Is kerosene an electrolyte or a non-electrolyte ?
How is a strong electrolyte different from a weak electrolyte?
Fill in the blank
A new substance is formed in a _______ change.
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.
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.
Show with the help of diagram of electronic configuration how the following compound is formed from the constituent atoms.
Water
Multiple choice:
Thermal decomposition of sodium carbonate will produce
Name: A greenish-yellow gas.
Give a chemical test to distinguish between the following gases.
CO2 and SO2
Give a chemical test to distinguish between the following gases.
NH3 and SO2
What is a chemical reaction?
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 – Addition of water to quicklime.
Give balanced equation for the following conversion affected by heat alone on the substance:
Copper carbonate to copper oxide
Give a balanced equation for a reaction involving the evolution of gas on the addition of dilute acid to calcium carbonate.
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
Ammonium dichromate.
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?
Magnesium + oxygen → magnesium oxide.
2Mg + O2 → 2Mg O
