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प्रश्न
Write true or false :
Hydrogen sulphide has rotten egg smell .
विकल्प
True
False
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उत्तर
True
APPEARS IN
संबंधित प्रश्न
Give a reason.
Wasp sting is treated with vinegar.
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
TRUE \ FALSE
Weak electrolytes dissociate partially in their aqueous or fused state.
Name three reducing agents ?
Fill in the blank.
Melting of ice is a _______ change.
True or false
New substances are formed in a chemical change.
Fill in the blank:
The substances which undergo chemical change are called _______
A chemical equation is a statement that describes a chemical change in terms of
Complete the statement by filling the gap using an appropriate term from the terms given in the bracket.
(slow, coloured, arrow, fast, smell, milky, physical, product, chemical, reactant, covalent, ionic, octet, duplet, exchange, sharing, equality sign)
An ______ is drawn in between the reactants and products while writing the equation for a chemical reaction.
Give an example of a reaction where the following are involved
Catalyst
State the main characteristics of chemical reactions. Give at least one example in each case.
What is observed in performing the following :
| Hydrogen | Oxygen | Carbon dioxide | Chlorine | |
| Litmus test | ||||
| Apply a burning splint to the gas | ||||
| Colour of gas | colourless | colourless | colourless | greenish-yellow |
| Odour of gas |
Give a chemical test to distinguish between the following gases.
SO2 and Cl2
State the following reaction represent oxidation or reduction.
\[\ce{H->H+}\]
NPK are the primary nutrients for plants.
_____ is the basic material to manufacture urea.
A thick coating of a paste of Plaster of Paris (POP) is applied over the bandage on a fractured bone. It becomes hard on drying to keep the fractured bone immobilised. Can the change in POP be reversed?
Classify the following as physical or chemical properties
Most metal oxides form alkalis on interacting with water.
Rusting of iron 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 |
