Advertisements
Advertisements
प्रश्न
Fill in the blank:
The basic conditions necessary for a chemical reaction is _______
Advertisements
उत्तर
The basic conditions necessary for a chemical reaction is close contact .
APPEARS IN
संबंधित प्रश्न
Classify the following reaction as combination, decomposition, displacement, precipitation and neutralization. Also balance the equation.
\[\ce{NH3_{(g)} + HCl_{(g)} -> NH4Cl_{(s)}}\]
TRUE \ FALSE
Weak electrolytes dissociate partially in their aqueous or fused state.
True or false
New substances are formed in a chemical change.
Write true or false.
A chemical equation gives only qualitative information of a chemical reaction.
Balancing a chemical equation is based on
Explain by writing a word equation.
Respiration is a chemical change.
Show with the help of diagram of electronic configuration how the following compound is formed from the constituent atoms.
Potassium fluoride
Give reason for the following:
Silver nitrate solution is kept in coloured bottles.
Give an example of a photochemical reaction.
Give reason for the following:
A characteristic change of colour is seen when a piece of iron is added to copper [II] sulphate solution.
Give reason for the following:
The catalytic oxidation of sulphur dioxide to sulphur trioxide is represented by a double arrow {⇌}
between the reactants and products, formed in the 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 – Thermal decomposition of mercury [II] oxide.
Complete the table given below.
| Addition of dil. H2SO4 to FeS | Odour of gas evolved |
Give a balanced equation for the conversion of a soluble lead salt to an insoluble lead salt – formed as a white precipitate.
Higher order Thinking question
A very hot glass on putting in cold water cracks. What does this change indicate?
Chemists identify gypsum as a natural indicator.
Beating an egg to make a cake is a ______.
The simplest method of preventing rusting of iron is to coat it with oil, grease, or paint. The reason being ______.
Chemical changes are important in our day-to-day life. Give examples.
Both CO2 and H2 gases are ______.
