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प्रश्न
How do the following help in bringing about a chemical change?
pressure.
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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
Complete and balance the following chemical equations:
N2 + O2 →
Fill in the blanK
A .............is a substance which changes the rate of a chemical reaction without undergoing a chemical change.
Write the missing reactants and products and balance the equations.
\[\ce{KClO3 ->[heat]}\] ___________+ ____________
What do you observe when Iron nail is kept in copper sulphate solution for sometime.
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer
Which of the following is a reducing agent?
- oxygen
- chlorine
- hydrogen
- none of these
MATCH THE COLUMNS
| 1 . `H_2` + `CI_2` `→` 2HCI | a. displacement reaction |
| 2. `2FeCI_3`+ `H_2` `→` `2FeCI_2` +2HCI` | b. addition of an electronegative redical |
| 3. Fe + `CuSO_4` `→``FeSO_4` +Cu` | c. removal of an electronegative redical |
| 4. `2H_2O` +`4NO_2`+`O_2` `→` `4HNO_3` | d.reduction by adding hydrogen |
| 5. 3Fe +`3CI_2` `→` `2FeCI_3` | e.electrolysis of water |
| 6. `FeCI_3`+ 3NaOH `→``Fe(OH)_3``↓`+NaCI | F.double decomposition,precipitation reaction |
| 7.`2H_2O` `→` `2H_2``↑`+`O_2` | e. combination or synthesis reaction |
TRUE \ FALSE
Positively charged electrode is called the anode. True or false ?
State four conditions necessary for chemical reactions to take place.
A solution of a substance ‘X’ is used for white washing write the reaction of the substance ‘X’ named in (a) above with water.
Give an example of a reaction where the following are involved:
Close contact
Write the chemical reaction where the following changes are observed.
Gas is evolved
What is a chemical change? Give two examples of chemical change?
Distinguish by dilute sulphuric acid.
Copper and magnesium?
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.
Complete the table given below.
| Addition of dil. H2SO4 to FeS | Odour of gas evolved |
The chemical change is ______.
Photosynthesis is a chemical reaction that takes place in the presence of ______.
The percentage composition of Nitrogen in Ureas is ______.
Heat may evolve or be absorbed during a ______ change.
When magnesium is burnt in the air, a new substance is formed which is ______.
