Respuesta :
The melting points of the compounds from the choices are listed below:
a. C25H52 -> +47 to +56 degrees celsius
b. Hg -> -38.83 degrees celsius
c. CaCl2 -> +772 degrees celsius
d. CuO -> +1326 degrees celsius
It is evident from the listed melting points above that mercury (Hg) has the lowest melting point. This is why mercury is liquid at room temperature.
a. C25H52 -> +47 to +56 degrees celsius
b. Hg -> -38.83 degrees celsius
c. CaCl2 -> +772 degrees celsius
d. CuO -> +1326 degrees celsius
It is evident from the listed melting points above that mercury (Hg) has the lowest melting point. This is why mercury is liquid at room temperature.
Answer: Hg
Explanation: As we know that in case of hydrocarbons, as the size increases, vander waal forces become strong thus attract each other with a strong tendency thus C_{25}H_{52} is solid at room temperature. Its melting point is approximately 50°C.
Mercury is the only metal which exist as liquid at room temperature thus iy has lower melting point of -38.83 °C.
CaCl2 is and CuO are closely packed solids and thus have high melting point. The former one has melting point of 772 °C and th latter one has melting point of 1326°C.
Thus Mercury has lowest melting point out of the given options.
