Question
$$CaC{l_2}$$ is preferred over $$NaCl$$ for clearing ice on roads particularly in very cold countries. This is because :
A.
$$CaC{l_2}$$ is less soluble in $${H_2}O$$ than $$NaCl$$
B.
$$CaC{l_2}$$ is hygroscopic but $$NaCl$$ is not
C.
Eutectic mixture of $$\frac{{CaC{l_2}}}{{{H_2}O}}$$ freezes at $$ - {55^ \circ }C$$ while that of $$\frac{{NaCl}}{{{H_2}O}}$$ freezes at $$ - {18^ \circ }C$$
D.
$$NaCl$$ makes the road slipperty but $$CaC{l_2}$$ does not
Answer :
Eutectic mixture of $$\frac{{CaC{l_2}}}{{{H_2}O}}$$ freezes at $$ - {55^ \circ }C$$ while that of $$\frac{{NaCl}}{{{H_2}O}}$$ freezes at $$ - {18^ \circ }C$$
Solution :
Due to much lower freezing point of eutectic mixture of $$\frac{{CaC{l_2}}}{{{H_2}O}}.$$