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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.
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
Complete and balance the following chemical equations:
`"H"_2"S"` + `"CI"_2` `→`
Complete and balance the following chemical equations:
Zn + `"H"_2"SO"_4` `→`
(dil)
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Miscible liquids having slightly different boiling points can be separated by the
- evaporation
- distillation
- fractional distillation
- sedimentation
FILL IN THE BLANK
Distillation is a method of obtaining pure ............. from a solution.
TRUE \ FALSE
Positively charged electrode is called the anode. True or false ?
Name three reducing agents ?
What do you observe when :
an iron nail is kept in tap water for few days
Fill in the blank.
Melting of ice is a _______ change.
Define chemical reaction.
Fill in the blank:
In some chemical reactions an insoluble ________ is formed when two solutions are mixed.
Write true or false :
When iron and sulphur are heated together a grey mass is formed which is attracted by a magnet .
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
Give an example of a reaction where the following are involved
Pressure
Define Photochemical reaction
Give an example
Give reason for the following:
Silver nitrate solution is kept in coloured bottles.
Give reason for the following:
Molybdenum is used in the manufacture of ammonia.
Multiple choice:
Which of the following is not a characteristic of a chemical change?
What is a chemical change? Give two examples of chemical change?
Complete and balance the following reaction:
NaCl(aq) + AgNO3(aq) →
What is observed in performing the following :
| Hydrogen | Oxygen | Carbon dioxide | Chlorine | |
| Litmus test | ||||
| Apply a burning splint to the gas | ||||
| Colour of gas | colourless | colourless | colourless | greenish-yellow |
| Odour of gas |
What do you observe when H2S is passed through a lead nitrate solution.
Give a chemical test to distinguish between the following gases.
NH3 and SO2
What do you observe when dilute sulphuric acid is added to the following:
Sodium Sulphide
What do you observe when CO2 is passed through lime water first and then a little in excess.
Distinguish by dilute sulphuric acid.
Copper and magnesium?
Select the correct answer for the following options:
The gas obtained when potassium chlorate is heated in the presence of a catalyst.
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
Zinc carbonate.
Rusting of Iron: undesirable change:: Dead plants turn into manure: ______.
Define the following term:
Chemical change
