Answer:
Adding salt to the water increases the density of the solution because the salt increases the mass without changing the volume very much. When you add table salt (sodium chloride, NaCl) to water, the salt dissolves into ions, Na+ and Cl-. The volume increases by a small factor, but the mass increases by a bigger factor.
Explanation:
Answer:
not sure about 6 but 7 should be c
Explanation:
..
When it comes to physical changes like phase changes, there are two types of heat energy: sensible heat and latent heat. Sensible heat is the heat absorbed/released when you heat the substance but it doesn't change phase. An example would be heating lukewarm water. The substance is liquid all throughout. Latent heat, on the other hand, is the heat absorbed/released when there is a phase change. An example would be boiling water, because it changes liquid to vapor.
Hence, for freezing liquid, you use the latent heat, specifically the heat of fusion. The answer should be
2.5 g * (1 mol/18.02 g) * 6.03 kJ/mol = 0.84 kJ/mol
The answer is not in the choices. You only use Hvap if you boil water.
Isotopes are atoms of different elements which have the same mass.
