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प्रश्न
Give balanced equation for the following conversion affected by heat alone on the substance:
Copper nitrate to nitrogen dioxide
उत्तर
Action of heat on:
\[\ce{\underset{\text{[blue]}}{2Cu[NO3]2} ->[\triangle]\underset{\text{[black]}}{2CuO} +\underset{\text{Nitrogen dioxide}}{4NO2} + O2}\]
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संबंधित प्रश्न
How do the following help in bringing about a chemical change?
pressure.
Write a short note on the information derived from a balanced chemical equation.
Fill in the blank:
The substances which undergo chemical change are called _______
State four conditions necessary for a chemical reaction to take place.
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)
Oxygen is a ______ in respiration.
Show with the help of diagram of electronic configuration how the following compound is formed from the constituent atoms.
Sodium chloride
Give an example of a reaction where the following are involved
Heat
Write the chemical reaction where the following changes are observed.
Gas is evolved
Give a chemical test to distinguish between the following gases.
H2 and O2
Give a chemical test to distinguish between the following gases.
NH3 and HCl
Give a word equation for the following reaction.
Two gases which combine to give a solid.
A chemical reaction is often accompanied by external indications or characteristics which include –
- Colour change
- Effervescence or gas evolved
- Evolution or absorption of heat
- Formation of a precipitate.
With reference to each of the above indications, state the external indication seen during – Addition of dilute hydrochloric acid to silver nitrate.
A thick coating of a paste of Plaster of Paris (POP) is applied over the bandage on a fractured bone. It becomes hard on drying to keep the fractured bone immobilised. Can the change in POP be reversed?
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?
Match the following:
| 1. | Sodium Chloride | a. | CaSO41/2H2O |
| 2. | Calcium sulphate dihydrate | b. | C2H5Oh |
| 3. | Magnesium sulphate hydrate | c. | CaSO4.2H2O |
| 4. | Calcium sulphate hemihydrate | d. | NaCl |
| 5. | Phenol | e. | MgSO4.H2O |
Two chemical species X and Y combine together to form a product P which contains both X and Y
\[\ce{X + Y -> P}\]
X and Y cannot be broken down into simpler substances by simple chemical reactions. Which of the following concerning the species X, Y and P are correct?
(i) P is a compound
(ii) X and Y are compounds
(iii) X and Y are elements
(iv) P has a fixed composition
______ occurs in the absence of air and in the presence of micro-organisms such as yeast.
Magnesium + oxygen → magnesium oxide.
2Mg + O2 → 2Mg O
Why is spoiling food a chemical change?
