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प्रश्न
Distinguish by heating the following in dry test tubs.
Zinc carbonate, Copper carbonate and lead carbonate.
उत्तर
| Zinc carbonate | Copper carbonate | Lead carbonate | |
| Residue left | Zinc oxide(ZnO) | Copper oxide(CuO) | Lead Oxide (PbO) |
| Colour of residue | Yellow when hot and white when cold | Colour is Black solid. | Colour is yellow. |
| Gas produced | Carbon dioxide gas is produced. | Carbon dioxide gas is produced. | Carbon dioxide gas is produced. |
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संबंधित प्रश्न
Changes in which new substances are formed are called ______ changes.
The gas we use in the kitchen is called liquefied petroleum gas (LPG). In the cylinder, it exists as a liquid. When it comes out from the cylinder it becomes a gas (Change − A), then it burns (Change − B). The following statements pertain to these changes. Choose the correct one.
FILL IN THE BLANK
A .............. change is a temporary change.
FILL IN THE BLANK
The new substances formed during a chemical reaction are called the ..................
What are chemical reactions?
Differentiate between in Chemical reaction and chemical equation.
Name the type of chemical reaction shown by the following equation:
2Mg + O2 → 2MgO
State the conditions necessary for a chemical change or reaction.
What is a chemical change? Give two examples of chemical change?
What do you understand by 'chemical reaction'?
Give an example of the following chemical changes.
A reaction where colour change is noticed.
Write your observation and a balanced equation in the case of the following substances being heated.
Zinc carbonate.
On heating which of the following substances i.e. copper carbonate, zinc carbonate, washing soda, copper sulphate, zinc nitrate, copper nitrate, lead nitrate, ammonium chloride and ammonium dichromate – relate to the reaction given below.
A coloured substance which leaves a black residue and evolves two gases one of which is acidic and coloured and the other neutral and colourless.
Complete the table given below.
| Flame test for calcium chloride | Acid used for flame test |
Complete the statement by filling in the blank with the correct word:
The reddish-brown precipitate obtained during a double decomposition precipitation reaction between an iron salt and alkali is __________.
The percentage composition of Nitrogen in Ureas is ______.
Water boiling into water vapour is an example of chemical change.
Rusting of iron is ______.
Iron and rust are the same substances.
Magnesium + oxygen → magnesium oxide.
2Mg + O2 → 2Mg O
