Room temperature is above the critical point for temperature of Oxygen, which means a liquid can not be formed.  Even under great pressure at this temperature, it will not form a liquid, but instead a gas with some liquid characteristics.

1 cal = 1 gram H2O raised 1 degree Celsius.  Ice is 0 degree C.  4.184 J = 1 cal

 ..    ..:Cl--Cl: ..    ..

Ca2+ is an ion, with a +2 charge, meaning it is deficient of two of the electrons that normally occupy it's highest atomic orbital.