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प्रश्न
Fill in the blank:
In some chemical reactions an insoluble ________ is formed when two solutions are mixed.
उत्तर
In some chemical reactions an insoluble precipitate is formed when two solutions are mixed.
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संबंधित प्रश्न
Give one example that illustrates the following characteristics of a chemical reaction:
Change in state
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Compounds, which in their molten state allow an electric current to pass through them are called
- electrolytes
- non-electrolytes
- non-conductors
- none of these
TRUE \ FALSE
Temperature at which a liquid starts boiling is known as the boiling point of that liquid. True or false ?
Name the type of chemical reaction shown by the following equation:
2Mg + O2 → 2MgO
Complete the statement by filling the gaps using 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)
The white particles of baking soda disappear when put in lemon juice. This means that it is a ______ change.
Give an example of a reaction where the following are involved
Catalyst
Write the chemical reaction where the following changes are observed.
Physical state is changed
Give reason for the following:
Blue solution of copper sulphate changes to green when a piece of iron is added to this solution.
What do you observe? When
Sodium chloride solution is added to silver nitrate solution.
Complete the following table and write your observations.
|
Hydrogen sulphide |
Ammonia |
Sulphur dioxide |
Hydrogen chloride |
|
|
Shake the gas with red litmus solution |
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|
Shake the gas with blue litmus solution |
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|
Apply a burning splint to a gas |
Name: A brown gas
Name: Two nitrates that do not produce nitrogen dioxide on heating.
What do you observe when CO2 is passed through lime water first and then a little in excess.
Write your observation and a balanced equation in the case of the following substances being heated.
Ammonium dichromate.
What is a chemical reaction?
Complete the table given below.
| Addition of dil. H2SO4 to FeS | Odour of gas evolved |
State the following reaction represent oxidation or reduction.
\[\ce{H->H+}\]
Give a balanced equation for a reaction involving the evolution of gas on the addition of dilute acid to calcium carbonate.
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
Copper nitrate.
Circle the odd one out. Give reason for your choice
NPK are the primary nutrients for plants.
______ is not a chemical change.
Chemical change is a temporary change.
State whether the following statements are true or false:
When a candle burns, both physical and chemical changes take place.
Melting of wax is a change where a solid changes to a liquid state. Give one more such change which you observe in your surroundings
The simplest method of preventing rusting of iron is to coat it with oil, grease, or paint. The reason being ______.
Assertion (A): Cutting paper into very small pieces is an irreversible change.
Reason (R): Physical changes are always reversible.
The reaction of H2 gas with oxygen gas to form water is an example of ______.
When milk is mixed with coffee decoction, the colour of milk and decoction changes due to ______.
