Advertisements
Advertisements
प्रश्न
Fill in the blank
A catalyst either ................or ............... the rate of a chemical change but itself remains ............... at the end of the reaction.
Advertisements
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
What are chemical reactions?
Differentiate between in Chemical reaction and chemical equation.
Fill in the blank:
The substances which undergo chemical change are called _______
Copper carbonate when heated, it turns :
Explain the following reaction with one suitable example of Combination reactions .
Name the type of chemical reaction shown by the following equation :
Fe2O3 + 2Al → Al2O3 + 2Fe
A solution of a substance ‘X’ is used for white washing Name the substance ‘X’ and write its formula.
Give an example of a reaction where the following are involved
Heat
What do you observe? When
Sodium chloride solution is added to silver nitrate solution.
Give a chemical test to distinguish between the following gases.
HCl and H2S
Name the following:
The type of change physical or chemical involved – ‘during respiration in human beings’.
State the following reaction represent oxidation or reduction.
\[\ce{Cu++->Cu}\]
Differentiate between the following:
Neutralization reaction and a precipitation reaction.
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
Copper nitrate.
Burning of paper is a ______ change.
The percentage composition of Nitrogen in Ureas is ______.
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 |
Assertion (A): Cutting paper into very small pieces is an irreversible change.
Reason (R): Physical changes are always reversible.
What are the chemical reactions that occur in everyday life?
