Advertisements
Advertisements
प्रश्न
Distinguish by heating the following in dry test tubs.
Zinc nitrate and copper nitrate.
उत्तर
| Zinc nitrate | Copper nitrate | |
| Residue left | Zinc oxide(ZnO) | Copper oxide(CuO) |
| Colour of residue | Yellow when hot and White when cold | Black Solid |
| Gas produced | The gas produced is Nitrogen dioxide and oxygen(NO2 + O2) | The gas produced is Nitrogen dioxide and oxygen(NO2 + O2) |
APPEARS IN
संबंधित प्रश्न
FILL IN THE BLANK
........... electrolytes dissociate completely in aqueous state and allow large amount of electricity to flow through it.
How is a strong electrolyte different from a weak electrolyte?
Write true or false :
When potassium iodide solution is added to lead acetate solution a red precipitate is formed.
State what you would observe when the following substance is heated in a glass test tube red lead.
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)
A colourless solution of calcium hydroxide in a test tube turns ______ on blowing in it through a blow tube for some time.
Give an example of a reaction where the following are involved:
Close contact
Give reason for the following:
Colourless concentrated sulphuric acid in a test tube changes to blue on adding a small piece of copper to it.
Name Affects the acidified K2Cr2O7 paper and also turns lime water dirty milky.
What do you observe when HCI is passed through a silver nitrate solution.
Give a chemical test to distinguish between the following gases.
HCl and H2S
Distinguish by heating the following in dry test tubs.
Zinc carbonate, Copper carbonate and lead carbonate.
Give a word equation for the following reaction.
A compound which on heating shows – colour change from brown to yellow.
Give a balanced equation for the conversion of an ammonium salt to a basic gas.
Which of the following is not an “element + element → compound” type reaction?
A bag of cement lying in the open gets wet due to rain during the night. The next day the sun shines brightly. Do you think the changes, which have occurred in the cement, could be reversed?
Write some materials prepared by chemical changes.
Arrange the following statements in correct sequence:
- One side is water-loving and other water-hating molecules.
- When you agitate the cloth, the dirt is surrounded by many molecules and taken away from the cloth.
- The dirt surrounded by the detergent molecules floats in the water making it dirty.
- Finally, the cloth is clean.
- The detergent molecules have two sides.
- Water hating goes and joins with dirt and oil in the cloth while the water-loving joins with the water molecules.
Write five changes in the characteristics of a substance that can take place during a chemical change.
Photosynthesis is a chemical charge. Justify your answer.
What is the difference between reactants and products?
