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प्रश्न
Fill in the blanK
A .............is a substance which changes the rate of a chemical reaction without undergoing a chemical change.
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उत्तर
A catalyst is a substance which changes the rate of a chemical reaction without undergoing a chemical change.
APPEARS IN
संबंधित प्रश्न
State whether the following statement is true or false. In case a statement is false, write the corrected statement.
Condensation of steam is not a chemical change.
How do the following help in bringing about a chemical change?
catalyst .
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
In a double decomposition precipitation reaction both the reactants must be ............ soluble.
TRUE \ FALSE
The evolution of a gas during a chemical reaction is shown by an arrow pointing downwards. True or false ?
Fill in the blank
A new substance is always formed in a _______ change.
Write true or false .
A black residue is formed when sugar is heated .
Balance the following equation :
Fe + H2O → Fe3O4 + H2
Explain by writing a word equation.
Limestone powder disappears on adding to dilute hydrochloric acids.
Show with the help of diagram of electronic configuration how the following compound is formed from the constituent atoms.
Sodium chloride
Give an example of a reaction where the following are involved:
Close contact
Give an example of the following chemical changes.
A reaction involving
(i) Change of state
(ii) formation of precipitate
Name: Gas with rotten egg smell.
State the original colour of the following substance and colour of residue obtained after heating.
Lead nitrate
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.
Select the correct answer for the following options:
The pale blue precipitated obtained when copper [II] sulphate reacts with sodium hydroxide.
Give reason for the following:
Electrolytic decomposition of water is a reaction involving change of state.
Differentiate between the following:
Neutralization reaction and a precipitation reaction.
______ change results in the change of the substance.
