Explain what would be the best observation when sodium chloride and sodium sulphate solutions are mixed​

These two solutions react to form a white insoluble precipitate.

BaCl2​+Na2​SO4​→2NaCl+BaSO4​↓

This is a double displacement reaction as the two compounds exchange their ions to form two different compounds.

Explanation:

the best answer is d because the strong cohesion is caused by the ability of water molecules to undergo hydrogen bonding.

a is incorrect because when water solidifies, it becomes   ice, which expands and occupies a bigger volume for the same mass of water in its liquid state.

b is incorrect because water has high surface tension. besides bonding to itself it hydrogen bonds to other molecules at the top decreasing possibility for breaking of attractive forces.

c is incorrect because the water molecule has oxygen which is highly electronegative and so pulls the electron pair towards itself creating a dipole moment, making the molecule polar.

e is incorrect because water has strong adhesion, ability to stick to other molecules such as glass because of this molecules having stronger hydrogen bonding than water.