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प्रश्न
State what you would observe when the following substance is heated in a glass test tube Copper (II) carbonate Red lead .
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उत्तर
CuCO3 → CuO + CO2 ↑
The blue-green powder turns black and a colourless gas is evolved which extinguishes a burning flame.
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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.
Iron and rust are the same substances.
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catalyst .
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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
What are chemical reactions?
Define electrolysis.
Fill in the blank
A new substance is always formed in a _______ change.
Fill in the blank.
Melting of ice is a _______ change.
Give a chemical test to distinguish between the following gases.
SO2 and Cl2
Write your observation and a balanced equation in the case of the following substances being heated.
Ammonium chloride
Give examples of exothermic reactions i.e. heat evolved in each of the following:
(a) reaction between a solid and a liquid
(b) reaction between two gases
Give two examples of exothermic reactions seen in everyday life.
Select the correct answer for the following options:
The gas which reacts with oxygen to give a neutral liquid.
When an aqueous solution of potassium chloride is added to an aqueous solution of silver nitrate, a white precipitate is formed. Give the chemical equation of this reaction.
When magnesium is burnt in the air, a new substance is formed which is ______.
The chemical formula of rust is ______.
Chemical changes are important in our day-to-day life. Give examples.
When carbon dioxide is passed through lime water ______.
______ is the chemical name of slaked lime.
