Which of the following substances when mixed with sand cannot be separ...
Sublimation method is used for separating substances which on heating change directly into vapour. Substances like iodine, ammonium chloride, naphthalene sublime on heating.
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Which of the following substances when mixed with sand cannot be separ...
Explanation:
When substances are mixed, they can often be separated through various physical methods such as filtration, evaporation, or sublimation. Sublimation is the process by which a solid directly converts into a gas without passing through the liquid phase. However, not all substances can undergo sublimation, and some substances may not be separated from sand through this process.
Sodium Chloride (NaCl):
Sodium chloride is a compound that cannot undergo sublimation. It has a high melting point of 801°C and boils at 1465°C. Therefore, when mixed with sand, it cannot be separated by sublimation.
Ammonium Chloride (NH4Cl):
Ammonium chloride is a compound that can undergo sublimation. It has a relatively low melting point of 338°C and sublimes at this temperature, meaning it can convert directly from a solid to a gas. Therefore, when mixed with sand, it can be separated by sublimation.
Iodine (I2):
Iodine is a substance that can undergo sublimation. It has a low melting point of 113.7°C and sublimes at this temperature. Therefore, when mixed with sand, it can be separated by sublimation.
Naphthalene (C10H8):
Naphthalene is a compound that can undergo sublimation. It has a relatively low melting point of 80.2°C and sublimes at this temperature. Therefore, when mixed with sand, it can be separated by sublimation.
In summary, sodium chloride is the only substance in the given options that cannot undergo sublimation. Therefore, when mixed with sand, it cannot be separated by sublimation.
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