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प्रश्न
True or false
New substances are formed in a chemical change.
पर्याय
True
False
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उत्तर
True
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संबंधित प्रश्न
State whether the following statement is true or false. In case a statement is false, write the corrected statement.
Formation of manure from leaves is a physical change.
State whether the following statement is true or false. In case a statement is false, write the corrected statement.
Iron and rust are the same substances.
Changes in which new substances are formed are called ______ changes.
How do the following help in bringing about a chemical change?
heat.
Name three biochemical catalysts found in the human body.
Fill in the blank
A catalyst either ................or ............... the rate of a chemical change but itself remains ............... at the end of the reaction.
What are biocatalysts ?
Is kerosene an electrolyte or a non-electrolyte ?
What are the characteristics of a chemical reaction ? A chemical reaction is characterised by an irreversible change in which a new substance is formed.
Fill in the blank:
In some chemical reactions an insoluble ________ is formed when two solutions are mixed.
Write true or false :
When iron and sulphur are heated together a grey mass is formed which is attracted by a magnet .
Name the type of chemical reaction shown by the following equation:
Fe + CuSO4 → FeSO4 + Cu
Match the pairs.
| a. | Photosynthesis | i. | Tendency to lose electrons |
| b. | Water | ii. | Reactant in combustion process |
| c. | Sodium chloride | iii. | Chemical change |
| d. | Dissolution of salt in water | iv. | Covalent bond |
| e. | Carbon | v. | Ionic bond |
| f. | Fluorine | vi. | Physical change |
| g. | Magnesium | vii. | Tendency to form anion |
Name: Two nitrates that do not produce nitrogen dioxide on heating.
State the original colour of the following substance and colour of residue obtained after heating.
Copper carbonate
Give a chemical test to distinguish between the following gases.
H2 and CO2
Write your observation and a balanced equation in the case of the following substances being heated.
Copper nitrate.
State the following reaction represent oxidation or reduction.
\[\ce{Fe++->Fe+++}\]
Which of the following is not an “element + element → compound” type reaction?
Collect information about the types of fuels used for cooking in your area. Discuss with your teachers/parents/others which fuels are less polluting and why.
