Answer: If a substance has a boiling point of 
then it is true that it will also change from a gas to a liquid at 78 °C while the gas loses energy.
Explanation:
The temperature at which vapor pressure of a liquid substance becomes equal to the atmospheric pressure is called boiling point of substance.
At the boiling point, liquid phase and vapor phase remains in equilibrium.
This means that as liquid phase changes into vapor phase and also vapor phase changes into liquid phase at the boiling point.
Thus, we can conclude that if a substance has a boiling point of then it is true that it will also change from a gas to a liquid at 78 °C while the gas loses energy.
Exothermic reaction is where there is release of energy during a reaction
The enthalpy of exothermic reaction is negative
The relation between energy of products, reactants and enthalpy of reaction is
Enthalpy of reaction = sum of enthalpy of formation of products - sum of enthalpy of formation of reactants
.
As enthalpy of reaction is negative, it means the enthalpy of products is less than the enthalpy of reactants so answer is
:
In an exothermic reaction the energy of the product is less than the energy of the reactants.
Answer:
Volcanoes cool off the earth by emitting heat from its interior. They also add islands and for example, Hawaii was created / is made out of volcanoes. The deposits from volcanoes can also be used for building materials. Volcanic explosions have caused the atmosphere and oceans to form. Volcanic deposits also create land which is fertile.
A solvent (from the Latin solvō, "I loosen, untie, I solve") is a substance that dissolves a solute (a chemically distinct liquid, solid or gas), resulting in a solution. A solvent is usually a liquid but can also be a solid or a gas. The quantity of solute that can dissolve in a specific volume of solvent varies with temperature. Common uses for organic solvents are in dry cleaning (e.g., tetrachloroethylene), as paint thinners (e.g., toluene, turpentine), as nail polish removers and glue solvents (acetone, methyl acetate, ethyl acetate), in spot removers (e.g., hexane, petrol ether), in detergents (citrus terpenes) and in perfumes (ethanol). Water is a solvent for polar molecules and the most common solvent used by living things; all the ions and proteins in a cell are dissolved in water within a cell. Solvents find various applications in chemical, pharmaceutical, oil, and gas industries, including in chemical syntheses and purification processes.
source: wikapedia
