N2(g) + 3H2(g) ⇌ 2NH3(g)

How will the reaction be affected if the pressure on the system is decreased?

Reaction equilibrium will shift to the left (higher molar volume side of process).

Explanation:

For gas phase reactions, changes in pressure-volume conditions cause a stress on the process equilibrium shifting away from the applied pressure-volume change.

LeChatlier's Principle states for a gas phase reaction at equilibrium ...

if the pressure is increased (volume decreased) the reaction will shift toward the lower molar volume side of the process.

if the pressure is decreased (volume increased) the reaction will shift toward the higher molar volume side of the process.

if the sum of molar volumes of reactants equals the sum of molar volumes of products, changes in pressure-volume conditions will NOT affect the equilibrium stability.  Example => H₂(g) + Cl₂(g) ⇄ 2HCl(g) will not be affected by P-V changes as ∑Vm(reactants) = ∑Vm(products).

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.