<span>boron trichloride + water → boric acid + hydrochloric acid</span>
I would say water; water is extremely polar, and this is why it can break one of the strongest bonds, ionic bonds. NaCl, as you probably know, is a salt, and dissolves in water. However, the ionic bond holding the Na+ and the Cl- is extremely strong; the boiling point of NaCl is at 1413 degrees celcius (water is at 100 degrees celcius). This means that it requires A LOT of energy to break the bond, but water is able to dissolve and break the bond very easily. It is very polar, so I would answer your question with water. And the bond connecting the H and the O is a covalent bond.
We are going to use table salt, NaCl as an example.
(s) = solid, eg the salt you put on your food is a crystalline solid.
(l) = liquid, if you melt salt it take on a liquid form
(g) = gaseous, if you put enough energy in the salt will turn into a gas.
(aq) = aqueous, meaning in water or another solvent. If you put some table salt in water and stir it, it will dissolve, the NaCl molecules dont get destroyed but they dissolve becoming part of the liquid.
Viscosity is related to the parallel shear force acted by the fluid. In lay man's term, viscosity is the ease of how the fluid flows. The faster the flow is, the lower the viscosity (and vice versa). On the other hand, osmolarity pertains to the concentration of a component in a mixture expressed in number of solute particles per liter of the mixture.