Since it depends on vapor pressure, it varies depending on the temperature at which it's measured.
At its boiling point at 1 atm, Water requires 539.43 calories per gram, 40.65 kj/mol, or 2257 kj/kg.
Hydration enthalpy is the energy released when 1 mol of a substance is dissolved into a solution. It is always negative, as attraction bonds (e.g. dative, ion-dipole) are being formed.
Enthalpy is temperature dependant,
You will have to use a table such as the following,
http://www.thermexcel.com/english/tables/eau_atm.htm
104.86kJ/kg or 25.04kcal.kg if you take room temperature to be 25 degrees Celsius
143.6 btu/lb
the atoms (or molecules) within the substance move slower, as temperature decreases.
The temperature of the water/salt solution will equalize to room temperature.
It doesn't
Enthalpy is a state function, and to a first approximation does not depend on temperature. So the change in enthalpy to go from solid to a gas directly (sublimation) at some temperature is equal to the sum of the enthalpies associated with going from a solid to a liquid (fusion) and going from a liquid to a gas (vaporization) at other temperatures.
Alcohol, water, oil, and mercury come to mind.
Enthalpy is the amount of energy in a system and when this changes (when a reaction happens), the energy is either released (exothermic) or absorbed (endothermic) and this energy is usually released or absorbed as heat. Therefore when the enthalpy decreases, heat is released from the system making it exothermic. In contrast, when the enthalpy increases, heat is absorbed making it endothermic.
Temperature doesn't give the whole picture when you talk about boiling. A more useful property to talk about is enthalpy. Enthalpy is the energy held by the water. Prior to the boiling point, enthalpy and temperature both rise linearly. At the boiling point, temperature stops rising, but enthalpy continues to rise until it becomes steam. If you were to continue adding energy to the steam, it's temperature would rise again. The amount of energy that must be added to water to get it from water just at the boiling point to steam is the latent heat of vaporization and is equal to the enthalpy rise discussed in the previous paragraph. The latent heat of vaporization and the temperature where boiling will occur are dependant on the pressure.
the atoms (or molecules) within the substance move slower, as temperature decreases.
Room temperature water is the same as room temperature which ranges from 14C-25C (59F-77F)
Because hydrogen molecule is very stable and it is because of high dissociation enthalpy of hydrogen molecule, it reacts slowly with chlorine at room temperature.
Room temperature air. The water keeps it fresher.
yes,at room temperature by decreasing the pressure we can boil the water.
Room temperature
Water is not solid at room temperature, unless the room is also a freezer.
The temperature of the water/salt solution will equalize to room temperature.
room temperature
cold water absorbs heat from the surroundings and revert to room temperature