Advertisements
Advertisements
प्रश्न
How do the following help in bringing about a chemical change?
pressure.
Advertisements
उत्तर
Some chemical reactions take place when reactants are subjected to high pressure.
e.g: Nitrogen and hydrogen when subjected to high pressure produce ammonia gas.
\[\ce{N2+3H2⇌[450°C][200 atm] 2NH3}\]
APPEARS IN
संबंधित प्रश्न
When baking soda is mixed with lemon juice, bubbles are formed with the evolution of a gas. What type of change is it? Explain.
What do you observe when iron nail is kept in copper sulphate solution for sometime.
TRUE \ FALSE
Evaporation of water is a physical change. True or false ?
What are homogenous reactions ?
Explain the type of reactions on the basis of the direction of reaction.
Fill in the blank
A change in which the substance can be brought back to its original state is called a _______ change.
Fill in the blank:
The substances formed as a result of a chemical reaction are called _______
Show with the help of diagram of electronic configuration how the following compound is formed from the constituent atoms.
Hydrogen chloride
Give reason for the following:
Colourless concentrated sulphuric acid in a test tube changes to blue on adding a small piece of copper to it.
Give an example of the following chemical changes.
A reaction involving
(i) Change of state
(ii) formation of precipitate
Give a chemical test to distinguish between the following gases.
SO2 and Cl2
What do you observe when dilute sulphuric acid is added to the following:
Sodium Sulphide
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 water to quicklime.
Complete the table given below.
| Heat on sodium chloride | Colour imparted to flame during flame test |
State the following reaction represent oxidation or reduction.
\[\ce{Fe++->Fe+++}\]
Anaerobic bacteria digest animal waste and produce biogas (Change – A). The biogas is then burnt as fuel (Change – B). The following statements pertain to these changes. Choose the correct one.
______ change results in the change of the substance.
Two chemical species X and Y combine together to form a product P which contains both X and Y
\[\ce{X + Y -> P}\]
X and Y cannot be broken down into simpler substances by simple chemical reactions. Which of the following concerning the species X, Y and P are correct?
(i) P is a compound
(ii) X and Y are compounds
(iii) X and Y are elements
(iv) P has a fixed composition
Write word equations for two chemical reactions with the help of materials given in the box.
| Air, copper sulphate, iron, vinegar, iron oxide, carbon dioxide, iron sulphate, copper, lime water, water |
