Question

For each system listed in the first column of the table below, decide (if possible) whether the change described in the second column will increase the entropy S of the system, decrease S, or leave S unchanged. If you don't have enough information to decide, check the "not enough information" button in the last column. Note for advanced students: you may assume ideal gas and ideal solution behaviour. System Change AS O AS < 0 AS = 0 O AS > 0 The solution is put into a semipermeable bag immersed in the water, and 50. mL of pure water flows through the bag into the sucrose solution. A 0.35 M solution of sucrose in water, and a beaker of pure water, both at 37. °C. not enough information O ASKO O AS = 0 A mixture of oxygen (O2) gas and hydrogen (H2) gas at 3 atm and 33°C. An additional 2.0 L of pure H, gas is added to the mixture, with the pressure kept constant at 3 atm. O AS > 0 o not enough information O AS < 0 O AS = 0 A liter of seawater at 15°C. The seawater is passed through a reverse-osmosis filter, which separates it into 750. mL of pure water and 250. mL of brine (very salty water). O AS > 0 not enough information x h ?

Answer 1

Entropy is the measurement of randomness.

The greater is the randomness/choas in a system, greater is its entropy.

Solids have very well packed structure thus least entropy.

Liquids have a little less packed structure or no packed structure, thus have more entropy than solid.

Gases have the most entropy as there molecules can move faster and in any direction.

Change 1.) sucrose and water system.

When the water molecules gets added to the sucrose solution, the sucrose molecules get more solvent to roam around and thus randomness increases.

This implies ∆S is positive.

∆S>0.

case 2.) Gases mixture:-

When to a mixture of gases more gas molecules are added, randomness increases, as more molecules og gases collide with each other and will roam here and there more, thus entropy increases.

∆S>0.

change 3.) When the sea water is purified. This water system have no impurities, thus have less molecules to roam around, less randomness.

∆S<0.