Salt will be less soluble in water if the "temperature is decreased". The kinetic energy brought about by temperature increases as the temperature increases. Because of these increase in kinetic energy, solvent molecules (water molecules) tend to break apart effectively the solute molecules (salt molecules).
Answer:
A. Atoms of new elements are found.
CO2 (s) + CO2 (g)
This is a physical change because only the state of matter changes, not the chemical makeup.
Molarity's formula is known as: Molarity(M)=moles of solute/liters solution.
In this case we are already given moles and liters so you just have to plug the numbers into the equation.
0.400 mol HCL/9.79L solution=0.040858M
If you were to use scientific notation, the answer will be: 4.1*10^-2, but otherwise, you can just use the decimals above and round appropriately as you see fit.