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प्रश्न
A solution of a substance ‘X’ is used for white washing write the reaction of the substance ‘X’ named in (a) above with water.
उत्तर
\[\ce{\underset{\text{quick lime}}{CaO} + H2O ->\underset{\text{slaked lime}}{Ca(OH)2}}\]
APPEARS IN
संबंधित प्रश्न
How do the following help in bringing about a chemical change?
pressure.
What are (i) positive catalysts and (ii) negative catalysts? Support your answer with one example for each of them.
Fill in the blank.
The formation of gas bubbles in a liquid during a reaction is called ......................
What do you observe when Iron nail is kept in copper sulphate solution for sometime.
MULTIPLE CHOICE QUESTIONS
Tick the most appropriate answer.
Reduction reaction is the exact opposite of
- displacement reaction
- decomposition reaction
- oxidation reaction
- none of these
What do you observe when :
an iron nail is kept in tap water for few days
Fill in the blank:
The basic conditions necessary for a chemical reaction is _______
Write true or false :
When potassium iodide solution is added to lead acetate solution a red precipitate is formed.
Explain the following reaction with one suitable example of Combination reactions .
Name the type of chemical reaction shown by the following equation:
NaOH + HCl → NaCl + H2O
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.
Give an example of the following chemical changes.
A reaction involving
(i) Change of state
(ii) formation of precipitate
Give a chemical test to distinguish between the following gases.
HCl and H2S
Give a chemical test to distinguish between the following gases.
SO2 and Cl2
What do you observe when CO2 is passed through lime water first and then a little in excess.
Distinguish by dilute sulphuric acid.
Sodium Sulphite and sodium carbonate?
Explain the term ‘chemical reaction’ with special reference to – ‘reactants’ and ‘products’.
Give reason for the following:
Electrolytic decomposition of water is a reaction involving change of state.
Give balanced equation for the following conversion affected by heat alone on the substance:
Ammonium dichromate to nitrogen
Complete the table given below.
| Addition of dil. H2SO4 to zinc | Test for gas evolved |
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
Copper nitrate.
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.
______ change results in the change of the substance.
Water boiling into water vapour is an example of chemical change.
If you leave a piece of iron in the open for a few days, it acquires a film of brownish substance, called rust.
Can you change rust back into iron by some simple method?
If you leave a piece of iron in the open for a few days, it acquires a film of brownish substance, called rust.
Do you think the formation of rust from iron is a chemical change?
When magnesium is burnt in the air, a new substance is formed which is ______.
Write a note on the following:
Curdling of milk
______ is the chemical name of slaked lime.
