Advertisements
Advertisements
प्रश्न
Explain with the help of balanced equations, how precipitation reactions are used for identifying the positive radicals in three different salts, each having a different cation [positive ion].
Advertisements
उत्तर
Precipitation reactions are used to identify the positive ions from their colours.
\[\ce{CuSO4 + 2NaOH->Na2SO4 + \underset{\text{pale blue ppt.}}{Cu[OH]2 v}}\]
identified ion is \[\ce{Cu^2+}\]
\[\ce{FeCl3 + 3NaOH->3NaCl + \underset{\text{reddish brown ppt.}}{Fe[OH]3 v}}\]
identified ion is \[\ce{Fe^3+}\]
\[\ce{Pb[NO3] + 2NaOH->2NaNO3 + \underset{\text{chalky white ppt.}}{Pb[OH]2 v}}\]
identified ion is \[\ce{Pb^2+}\]
APPEARS IN
संबंधित प्रश्न
Complete and balance the following chemical equations:
Zn + `"H"_2"SO"_4` `→`
(dil)
Give reason.
Acidic soil is treated with quick lime.
Name the type of chemical reaction shown by the following equation:
Fe + CuSO4 → FeSO4 + Cu
Match the pairs.
| a. | Photosynthesis | i. | Tendency to lose electrons |
| b. | Water | ii. | Reactant in combustion process |
| c. | Sodium chloride | iii. | Chemical change |
| d. | Dissolution of salt in water | iv. | Covalent bond |
| e. | Carbon | v. | Ionic bond |
| f. | Fluorine | vi. | Physical change |
| g. | Magnesium | vii. | Tendency to form anion |
Write the chemical reaction where the following changes are observed.
Physical state is changed
Give a chemical test to distinguish between the following gases.
HCl and Cl2
Give reason for the following:
A characteristic change of colour is seen when a piece of iron is added to copper [II] sulphate solution.
Name the solid residual product formed reaction and state its colour during – thermal decomposition of the following substance.
Zinc carbonate.
Give an example of a chemical reaction for the following situation:
A change in colour is observed
Magnesium + oxygen → magnesium oxide.
2Mg + O2 → 2Mg O
