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प्रश्न
Give a chemical test to distinguish between the following gases.
NH3 and HCl
उत्तर
| Ammonia | Hydrogen chloride |
| Litmus test: Moist red litmus blue. | Litmus test: Moist blue litmus paper red. |
APPEARS IN
संबंधित प्रश्न
How do the following help in bringing about a chemical change?
heat.
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Reduction reaction is the exact opposite of
- displacement reaction
- decomposition reaction
- oxidation reaction
- none of these
Fill in the blank.
Melting of ice is a _______ change.
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)
Electron ______ is complete in each hydrogen in a hydrogen molecule.
Explain by writing a word equation.
Limestone powder disappears on adding to dilute hydrochloric acids.
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
Electricity
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.
Multiple choice:
A reaction of a type: AB + CD → AD + CD, involves
What do you observe when CO2 is passed through lime water first and then a little in excess.
Write your observation and a balanced equation in the case of the following substances being heated.
Zinc carbonate.
Distinguish by dilute sulphuric acid.
Copper and magnesium?
Give reason for the following:
Electrolytic decomposition of water is a reaction involving change of state.
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 water to quicklime.
Give balanced equation for the following conversion affected by heat alone on the substance:
Ammonium dichromate to nitrogen
Give two examples where a chemical reaction is accompanied by a change in colour of the reactants and products on completion of the reaction.
The chemical change is ______.
True or False. If false, give the correct answer.
Taking a glass of water and freezing it by placing it in the freezer is a chemical change.
Classify the following processes into physical or chemical changes:
(i) Beating of aluminium metal to make aluminium foil.
(ii) Digestion of food.
(iii) Cutting of a log of wood into pieces.
(iv) Burning of crackers.
______ is the chemical name of limestone.
