Answer:
Take 100 ml of a 18 molar solution. The total number of moles is (1 liter/1000 ml) 100 ml 18 moles is 1.8 moles.
1.5 moles in 1 liter so If 1.1 liters of water is added, the total volume is 1.2 liters and 1.8 moles are dissolves in it. 1.8 moles/ 1.2 liters is 1.5 moles per liter.
-58 °C
The melting point is the same as the freezing point.
Answer:

Explanation:
First, we find in the tables the ΔH of formation of each compound. As you can see in the (image 1)
Then we solve the ecuation for ΔH°reaction
ΔH°reaction=∑ΔH°f(products)−∑ΔH°f(Reactants)
ΔH°reaction= (-2* 393.5 - 2*285.8) - (52.4 + 0) kJ/mol
ΔH°reaction = -1.41 *10^3 kJ/mol
Dmitri Mendeleev, he realized that the physical and chemical properties of elements were related to their atomic mass and arranged them into groups (columns)