Why is solid CaCl2 spread on roads in cold countries, during winter season ?
Dear Student,
CaCl2 is spread on roads in cold countries to decrease the melting point of ice. Addition of calcium chloride over the ice results in depression in the freezing point of the ice.
Calcium chloride dissociate into 3 ions.
CaCl2 ----> Ca2+ + 2Cl-
Ions formed interfere with the network of H2O molecules in ice and causes depression in the freezing point due to which ice melts readily on addition of CaCl2
Depression in freezing point on addition of non volatile solute to liquid.
Addition of a non-volatile solute, in the pure liquid, the freezing point of the liquid is lowered as, the vapour pressure of the liquid is decreased, due to presence of non volatile solute particles at the surface of the liquid. Consequently, the vapour pressure of the solid phase of pure liquid will be lowered.
Regards
CaCl2 is spread on roads in cold countries to decrease the melting point of ice. Addition of calcium chloride over the ice results in depression in the freezing point of the ice.
Calcium chloride dissociate into 3 ions.
CaCl2 ----> Ca2+ + 2Cl-
Ions formed interfere with the network of H2O molecules in ice and causes depression in the freezing point due to which ice melts readily on addition of CaCl2
Depression in freezing point on addition of non volatile solute to liquid.
Addition of a non-volatile solute, in the pure liquid, the freezing point of the liquid is lowered as, the vapour pressure of the liquid is decreased, due to presence of non volatile solute particles at the surface of the liquid. Consequently, the vapour pressure of the solid phase of pure liquid will be lowered.
Regards